Just because one an GET a TIP ‘early’ doesn’t mean that one can actually enter Mexico without having a Tourist or RT visa standing. If you recall, when you got your TIP online you first were redirected to an immigration site where you made some ‘guarantees’ about your visa status.
Also although you can GET an online TIP up to 60 days in advance, you were asked with your online TIP application for the ‘date’ you intended to cross. This question, IMO, is to align the 180 day stay of your TIP and your FMM.
Also, no one ever said that the two documents were ‘joined at the hip’ as there are other things that can ‘tie’ the two together such as your US Passport #.
So, IMO, your revelation may just be.....irrelevant.