Edit: tl;dr: Given a few changes, yes they would.
In a historical sense, Lets say in 1938 the Franco-Soviet treaty of mutual assistance got a lot more focus put into it from the French side. Then the USSR sent them a secret telegram saying they want to invade Poland so they can create a frontier with Germany, which helps France by creating a potential two front war for Germany when they attack.
From what we know, would France be willing to throw Poland under the bus just to get that much vaunted two front war against Germany?
And if France did accept the USSRs proposal, would Britain ever dare to go to war over Poland without France helping them?
Well, depending when we start fooling around in history the poles should worry more about being thrown to the germans by the french for an alliance. Or at least to be coerced into concessions. Several of the concessions to Hitler were driven by the want to have a strong buffer against the Soviets and communist influence. And Hitler as a rabid anti-communist was seen as the perfect man for that. And the sentiment persisted (but lost popularity) until '39 and the war declarations.
That said, if the french take a hard-left turn or grow considerably more hawkish in their outlook (say enough people are in favor for immediate aggression upon Rhineland), the answer could very well be "yes". The french logic would be that the russians can stall the germans long enough for the french army to strike the killing blow.
Of course, hindsight applies to both. And in HOI4, communist France can ally the UdSSR.
Its still impossible because Hitler also wanted polish land. He wanted all land east of Germany.
Sigh. As already pointed out, quite a bit of that "polish land" was seen at the time as "german land held by Poland" not only by germans. And if you want to peddle polish maximalist rethoric, I'll remind you that thats only funny as long as you stand on the winning side.
Do remember that the nazis did not start out as their 1945 incarnation. There were people like Hermann "I decide who is a jew" Göring or the Strasser brothers. So, if needs must, you can rewrite the ideology to accomodate the poles. I can think of at least two ways ad hoc. Of course, both include blaming someone else for the previous polish-german conflicts. No prizes for guessing whom. And of course its hypcritical. But hey, ideologues have proven to be quite good at that sort of thing.
In addition, a nazi-polish alliance would require some shifts in the internal power structure of both nations. And yes, the poles would probably loose Danzig and Posen. But in turn there will be consoldiation with lithuanian (port), russian (territory) and other stuff (some extraterritoriality). Funnyly enough, it could actually work out. Would suck for any non-pole or -german.
About Japan... Actually, Interwar border conflicts for the Japan have ended with exactly wiping the floor with them, just due to it happening in the Far East it never did go for Europe as something "worth noticing" though it has efficiently turned Japan to the expansion into European colonies in the South.
And add that. The japanese were still seen as primitives. And the whole anti-communist thingy.