I agree with most of what you said. Love has 2 years left plus a player option in 2019-2020. This is basically the same as Butler's contract, Love will most likely opt out of his contract. I do think Griff would have been able to figure out a package to get Butler if he didn't leave.
I really believe though that the difference in Gilberts and Griff's vision is Big 4 vs Big 3. There are reports that Gilbert wanted Griff to be more aggressive. Swapping Love for Butler and keeping the rest of the roster the same isn't aggressive. What would be aggressive is swapping out 3 of our players for Melo, going after replacements in free agency, resigning Korver and trading him at the deadline.
I think the differing opinions between Griff and Gilbert we're about the reshaping of the roster. Going forward Griff would have to admit failure with the majority of his trades and move the guys he acquired in the past couple seasons. All the players he acquired are the ones we are talking about trading, Love, Frye, Shump, and Korver. JR might be the lone guy left from Griff's trades and it's open knowledge he had to be convinced to do it.
I believe Indiana could call Gilbert right now and offer a straight up Paul George for Tristan Thompson deal, and Gilbert would decline it based on player control....he's not giving away long term assets for a guy who could walk this off-season. It sounds asinine but I believe it to be true.....