They are basically going to be DOSing a huge segment of users who've previously had that header set on their browsers...they're also violating the OMB mandate that requires TLS for all government sites...it is a rather strange move, I can't imagine there is a good reason for it.

EDIT If it is for portal.uspto.gov then HSTS is a non-issue but still a very bad move.

doesn't seem to show anything for the domain