That's a loser mentality.
What mentality do you expect with 10% market share? You can't just walk into the show guns blazing and expect a hit against Nvidia, can you?
Release a fast product at a reasonable price and that's it. If nvidia wanted to they would have already kicked amd out of the market, it doesn't even make sense to try to do anything about it. 5090 - 900$ msrp - 5080 = 500$ msrp, there you go, amd is now back to consoles.
That is exactly what AMD is trying to avoid in my opinion.
Think about it... let's say they released the 9070 XT now at x USD. The guys at Nvidia could watch the reviews and adjust prices accordingly. Then, in March, every review would praise the 5070 for being such a good value card, while everybody would have long forgotten about the 9070 XT.
On the other hand, if you wait, don't disclose anything, and let the 9070 XT release at the same time as the 5070, then the 9070 will take the value crown, while the 5070 will go down in reviews as an overpriced piece of turd. Sure, it'll be successful regardless, because Nvidia is Nvidia (I'll say no more), but those bad reviews of the 5070 might sway a couple more people towards the 9070 XT.
Edit: Like you yourself just said, there would be no point in trying to play one-hit-wonder against a much stronger opponent. No, this is a tactical game, you have to wait for them to make a mistake.
So in what universe does nvidia care about competing with AMD in the gpu market? They don't even know who amd is.
It's not about Nvidia. It's about AMD playing poker and not showing their cards ahead of time.
The goal is not to defeat Nvidia, but to claw back some market share, remember? Why would they not use every opportunity they get?