Why are we surprised at Microsoft's actions?
Surely this is just a simple case of Embrace, Extend, Extinguish in full flight.
They refused to take part in the ODF development because they couldn't take control and make it proprietary. Now they can negotiate from a position of strength. Having their own proprietary standard approved, means that during the negotiations "to bring order to the situation" they can demand certain aspects of their proprietary standard be incorporated. It will be fun to open a book on which bits of the ill defined "standard" they try to push in so that they can control the lot! Then the move after that is to make the open standard unworkable by anyone, so that we all have to shift back to Microsoft's own formats again "because they are the only formats that work".
Either the ISO has the round objects to stand up to this, or all international standards should be open to be bought by any wealthy bully.
Paris knows what to do with a bully.