This is just pure unadulterated propaganda by The Economist, as is so often the case with their coverage of China (reminder that, if you read The Economist, the Chinese economy should have collapsed more or less every year for the past 20 years).
I actually come from a country - France - where our minorities did actually get squashed, so I have a pretty decent understanding of what that concretely means.
For instance in France our regional languages (Basque, Alsacien, Corsican, Breton, Occitan, etc.) have ZERO official status, cannot be used in government, and - under French law - were prohibited in classrooms under threat of punishment (kids at school were made to wear a necklace of shame around their neck if they spoke their regional language: fr.wikipedia.org/wiki/V…).
The first line of Article 2 of the French constitution (en.wikipedia.org/wiki/A…) - as amended in 1992 - specifies that French is the exclusive language in France and constitutionally excludes every other language from any official role whatsoever.
There was, in France, an official policy of linguicide. The net result, according to official French statistics (ined.fr/fr/publications…), is that regional languages like Corsican or Breton went from being spoken in 70%-80% of local families at the end of WW1 down to sub-10% numbers by the end of the 20th century. Even Alsacien, the most resilient regional language, still saw its transmission rate collapse from 70% to 18% in just 2 generations.
That, folks, is "squashing."
Same thing, incidentally, in the UK - The Economist's own country: a reminder that in Wales schools used the "Welsh Not" (en.wikipedia.org/wiki/W…), a token of shame that a child would need to wear around their neck if they were heard speaking Welsh.
Compare and contrast this with this new Chinese law.
First of all, fact is that if you look at minorities with their own language in China, the immense majority of them still speak it and use it in their daily life.
For instance, a 2017 survey conducted by 国家语委 (the National Language Commission, the authoritative Chinese body on language policy), only 30% of people in Tibet had functional Mandarin proficiency (tibetology.ac.cn/2023-0…). In other words, Tibetan, not Mandarin, remains the dominant working language of daily life for the overwhelming majority of the population in Tibet.
Same story with Mongolian: according to China's Sixth National Census (2010), 85.25% of ethnic Mongols still used Mongolian in daily life (nmlr.muc.edu.cn/info/11…).
Which means, as a starting point, that China already did a far better job than virtually any Western country at protecting their minority languages. Important context when we're speaking about Western media lecturing China on the topic...
Heck, a good case could be made that they did TOO GOOD a job given that - among some ethnic minorities - most people speak ONLY their regional language, and can't even speak Mandarin, which is actually one of the main points of the new law.
So let's look at this new law (full text here: neac.gov.cn/seac/xwzx/2…).
Does it officially recognize and protect minority languages? Yes, the law literally says "The state respects and protects the learning and use of minority languages and scripts, promotes the regulation, standardization, and digitalization of minority languages."
Does it ban minority languages in schools? No. The new law does tilt education further toward Mandarin - requiring nationally unified textbooks and designating Mandarin as the basic language of instruction - but it does not abolish minority-medium schools (民族语授课学校 in Chinese, literally "minority-language-instruction schools") which can continue to operate with state funding in their respective regions.
Does it ban minority languages from government? No. Article 15 explicitly states that "where relevant laws require documents to be issued in minority languages, both the national common language version and the minority language version shall be provided" (依照有关法律规定需要使用少数民族语言文字发布文书的,应当同时提供国家通用语言文字版本和少数民族语言文字版本).
Does it ban minority languages from public signage? No. The law requires Mandarin to be displayed "prominently" alongside minority scripts in public settings - not instead of them.
Does it undermine autonomous regions? No. Article 8 of the new law explicitly reaffirms "upholding and improving the system of ethnic regional autonomy" (坚持和完善民族区域自治制度). Which means that the 1984 Regional Ethnic Autonomy Law remains in force, with their local regions' legal authority to adopt regulations suited to local ethnic conditions.
So all in all, what you CAN say is that the new law does indeed promote Mandarin and pushes to ensure every Chinese citizen can speak a common national language - which is, frankly, a pretty normal thing for any country to expect.
What you CANNOT say - unless you are writing propaganda rather than journalism - is that this law "squashes" 55 ethnicities. Actual squashing is hanging a wooden clog around a child's neck for speaking his mother tongue. Actual squashing would be making minority languages or culture anticonstitutional.
A law that funds minority-language preservation, preserves minority-medium schools, reaffirms regional autonomy, requires bilingual government documents and operates under a Constitution whose Article 4 guarantees all ethnic groups "the freedom to use and develop their own spoken and written languages and to preserve or reform their own traditions and customs" is not "squashing" anything.
It's a level of minority-language and cultural protection that the French Republic - or the UK - has never offered its own citizens in its entire existence.