I agree. this is really TT doing. the same issue arises with Win 7 for TT 2020 returns. TT says it will not allow installation for the 2020 software on computers runiing Win 7. Win 7 will still be ok for online prep.
TT does not want its software running on an OS that may have unpatched flaws. So desktop users with win 7 face the same problem you do. it is also true that updates needed for certain software to run can be incompatible with the current OS. Put another way, MS and Apple don't want to spend the time and money necessary to produce the updates to keep your system safe from flaws in their OS and other software.
for me, I was able to create adual boot system, so I'll be able to keep Win & and use win 10 solely for TT.
