While it is really a lot, as opposed to ‘too little’, it is definitely too late.
I do not think the open source community should care for two reasons. On the one hand, there is nothing M$ is able to offer, now or in the foreseeable future, that has not already been available to open sourcers. On the other hand Mr. Nadella might not last long in his byzantine environ, in spite of my deepest sympathies, and his successor will, I am afraid, steer back to basics, the good old days via the good old ways of splendid isolation.
M$, imho, does not intend to lure open sourcers, they merely attempt to stem the exodus. They are the underdogs on the brave new hunting ground where their established business model of selling inferior quality at a premium price is no longer applicable. The most dangerous moment in M$ corporate life, to paraphrase Alexis de Tocqueville, when they began to reform. Mr. Nadella is left with no alternatives.