I don't know who started posting this around this board, or why it persists, but it's patently untrue. Matching the RFA deal only meant that we couldn't trade him to Minnesota for the first year, and that we couldn't trade him anywhere else without his consent that first year. As of 7/18/13, there have been no restrictions on Batum trades.
If a team matches an offer sheet and retains its free agent, then for one year they cannot trade him without his consent, and during that year cannot trade him at all to the team that signed him to the offer sheet.
Didn't realize Taj is 30. If LMA left and the Blazers don't get a PF but do add a SF I'd consider a deal around those two. Taj has the better contract in a year. But those are a lot of ifs and unlikely. If LMA leaves we probably do more rebuilding and want a younger player from a Batum trade.