I don't think she should come back. It's one thing to do well in a couple of exos, especially where any nervousness would be on the other side. It's another to face these players under tournament conditions, with variant weather conditions, uncertain match times, and having to play a deeper field before squaring off against the top guns.
I don't neccessariy view the prospect of her winning a lower Tier event as being particularly damning for the tour. Virtually any player in the top 100 can win a lower-Tier event, and she's at least that good. And any of them can beat players at the top under the right circumstances. Plus, we are talking about someone who is the greatest player and greatest athlete who ever played the women's tour. She had a lot to give. If she could even get to 70% of her former game, that would be an excellent player.
The press, however, would opt for the most negative portrayal. If she wins, the tour sucks, if she loses, she's "tarnishing her legacy". However, if McEnroe were to come back and enjoy any success (he beat Courier routinely when Courier was still playing decent tennis, and allowed Arazi only 1 game), it would be hailed as a tribute to his greatness.