Could
even withdraw from this contest if they truly went on not to qualify?
Well, Turkey withdrew for being sore losers (without a good reason) and also for politically distancing themselves from Europe (Eurovision doesn't fit with the regime's ideas), so I guess nothing is impossible
However, I do think Russia wants Eurovision as a platform to promote themselves and spread, let's call it, an "adjusted image" (= propaganda), so I think Russia will stay regardless.
I mean if they really withdrew based on a potential no qualification with such a complete CRAP entry they sent this year, then they are having even more delusions of grandeur than Turkey had. No musical expert should even think of voting this to the final, and it has NOTHING to do with being anti or pro Russia, this is just a musical trainwreck that's the problem, if this wasn't Russia it would have been ranked in the bottom with almost 100% certain no qualification.