No. If MS didn't patent it but used it first, then they can win based on prior arts. You can't patent something that's already in used.
Nice idea. Trouble is you never quite know how these things will work out. And you have to deal with all the legal hassle. It's probably quicker and easier to patent it yourself, file that away somewhere and know that your safe. The cost of a patent application
is going to be considerably cheaper than a few hours of Microsoft's lawyer time!