Think Ray and KG are both mid-level exception guys at best next year. Only contending teams will want them and most won't have the cap space to make it happen (unless the Celtics do a sign and trade).
Yeah, I just can't see either getting more than the MLE. Neither will want to play for anything but a title contender. This means one of two scenarios is likely to play out.
-The Celtics renounce thier rights to both and land a major FA and a mid level FA. The C's then become serious title contenders, and KG and Ray agree to come back on Vet minimum deals.
-The C's decide to go for a more prolonged rebuild, but one or both still have a desire to play. Under this scenario, it is very likely any team they would consider would have only the MLE to sign them with.
If I had to guess, both would be willing to come back under the 1st scenario, while Ray is the only one likely to seek another team under the 2nd. KG may just straight up retire regardless.