The truly wise move for Entercom is to move WAAF's transmitter back to Paxton. Compared with West Boylston, it's a win-win. Do that and keeping 97.7 as a repeater makes a little more sense - for sales purposes.
The folly of moving WAAF to West Boylston is well documented. I have yet to travel anywhere in the market where WAAF comes in better than before, yet I go lots of places where the signal is not as good as it once was. For example, the W. Boylston tower should (theoretically) provide a superior signal into southern New Hampshire. It does not. All it did was weaken the signal enough to enable me to null out WAAF enough to get a fringe signal from WERZ in Nashua. That's something that wasn't possible there before.
If W. Boylston isn't better in S. New Hampshire, isn't noticeably better in Boston, isn't better in SE Mass, and hobbles the signal badly in central MA and elsewhere - then what good is it? Shut it off and move back to Paxton, which is an awesome stick. Besides, 97.7 covers you in those weak spots from Boston southward anyhow. This is a no-brainer.