I doubt Marriott will pull another huge acquisition just after they acquire Starwood.
The merging between Marriott and Starwood still quite messy up to this point.

Even if Marriott did have financial capability to acquire Accor, adding Accor integration to the mix will cause further issue and more disgruntled elites.

However, combining Marriott and Accor can create a true global hotel chain. As traditionally, each chain is quite weak at others strong area. And adding Accor less luxury brands to Marriott portfolio that mostly upper end offering will complement the footprint further.

In Asia, where both side have quite limited footprint, combined they will have better coverage and also Accor budget brands will plug Marriott lack of budget offering in the area. (Moxy's rate is still double than Ibis' (not budget) rate)

I guess if Marriott did pull this, the next sensible move will be securing a global apple supply chain to supply these millions of rooms with apple