I'm not saying it's right, but there's a chance Microsoft is feeling emboldened to get away with it based on Google's success steering search users to their own products.
Interesting follow-up there is that Facebook, in lifting so much of Snapchat for use across Facebook, WhatsApp, Instagram, and Messenger, has been giving Evan & team a pretty terrifying karmic kick in the rear... and though there might not be a connection here, Microsoft does own 1.~% of Facebook, after all.
Disclosure: own shares of SNAP; probably not selling soon (it either wins by chance or I write the whole company off as a loss). I don't exactly have the best opinion of the company.
In the beginning, it was just Microsoft.