That would probably be to AMD's advantage. There will always be some people desperate enough for an upgrade that they'll jump at the first to come along, even if something better is just a few months behind it.
Without wanting to re-open debates on AMD's marketing... I think launching slightly later than Nvidia played out very badly for AMD in the last couple of generations. The performance levels of the Nvidia cards were already well-known by the time AMD hit the shelves and, at that point, "a bit cheaper, competitive in raster, much worse at raytracing and upscaling" isn't a compelling sales pitch, at least at the higher end of the market. Go first and they get, however briefly, to have the fastest card around for a while (assuming their top-end card can beat the 4090, at least in raster).
Everything's pointing to it beating the 4080 or close to it, but agree with the rest.