As a longtime, somewhat reluctant, user of ultimate guitar I will say that often the chord annotations are not high quality. For instance, some annotators will have chord diagrams that show a voicing that actually rings out as e.g. Dsus4 but label it as D and use D throughout. Even more prevalent is songs where there are actually suspensions or extensions but which are written as plain major/minor throughout. I'm assuming Chordonomicon doesn't correct for this.

I don't think this changes your analysis (except maybe for rap? jazzy/laid back rap beats usually sound suspended/major 7th-y to me). I think it's interesting that this data is (likely) messy in a very domain-specific way.