From friends of mine who have worked at / are working at Microsoft, sadly this is a fairly common question, and the answer is "no" more often than you'd hope. Hopefully the new re-org helps them, because they desperately need to be rowing in sync.
Hell nowadays, I'm happy when people in the same team talk to each others, normally without band-aids: daily standup, weekly status, monthly get together, ...
Unless I'm missing something, Microsoft really has no reason to care if you want to target Windows XP. Their official response should be (and is) to upgrade to a supported release. Windows 7 was released almost 4 years ago and is supported until 2015/2020. How long can you complain that an ancient OS is no longer supported before you accept that fact?