It's an interesting thought experiment lol.
I think you'd get half the fanbase who'd be pretending this TCU team was a great team (like 100% of Buffs fans are doing) and then the other 50% of NU fans would be taking to the message boards to discredit our own win, like they always do.
We have the most self-hating fans in the country. We generally discredited every single win we had during the Frost era - other team had injuries, other team got screwed by the refs, other team had a short week, etc. The only win we didn't do that for was the MSU win in 2018 - that had universal acceptance. But pretty much every other win got completely discredited by a portion of our own fanbase.
Gotta admire CU fans' simplicity. They're all in on the fact they beat the #17 team in the country (I predict TCU will end up maybe 40-50th in the country by season's end & they might go 4-8). But CU was 1-11 last year, they actually should celebrate like they beat the '85 Bears today - I would.