TL;DR of @Lucas' article: first blaze has been more public than react for longer. But Blaze is a drain on Meteor resources, and react is more mature. They will start transitioning to using React underneath Blaze 2.0. React is more mature, advanced, but also takes longer to learn than Blaze. They recommend if you can take the time to learn React, do so. If you can't, then use Blaze but change how you use the templating. Don't reply on the implicit context of the template, instead.

But implying 'we already have react', blaze has been around for longer - changing the coupling of a whole framework takes time. I'm surprised that meteor is acting as fast as they are! Good job meteor team.

I think this post may answer at least a few of your questions.

meteor position's itself as a complete one in all package , and that is its selling point , react is owned and managed by facebook, which has it own reason and future for react, this most likely would conflict with meteor ( advent of relay and graph ql -- react is small and nimble , it designed to be flexible and align to new paradigm ) in such a situation, meteor would need to be assured of its future ,thus the need to heavily invest in blaze, even more now,, constantly being forced to bend to support all these frameworks and their quirks (angular, react ) , blaze is more tightly coupled with meteor and thus would always be inline with the ecosystem ,which is the what their trying to create .

--- personal take --- the future of Dev , is very unlikely to to be one stack ie complete package ( of course meteor is best for some people -that would always be true ) , different stack works better, though different, each rules it own world thus giving you the best of both world - - and yes am a huge meteor fan :)