I think it's both more than that and less than that. Unless I missed some news, Meta's newfound love for product openness has only really manifested in Llama and Threads—I haven't seen any evidence of shifts in their core products.
I think what's happened is that in both cases Meta knows that they don't really stand a chance of actually unseating the big players in that segment on their own, but that Meta can make a dent in their profit margins if they can dilute the value of owning that segment. Llama is squarely targeted at preventing anyone from owning AI. I think Threads is doing the same thing with microblogging. If Meta can't own a segment they're going to make darn sure that no one else can own it and use their profits from it to push Meta out of their core.
If it also makes the company look more palatable to regulators, that's a nice side effect, but I'm not sure it would work as the primary goal.