The value of Cole for the Phillies is the fact that they could probably afford to guarantee his 2019 option, especially if the Rangers pay for part of it (since the buyout alone is $6 million). He may also be willing to to take an extension (if it's low AAV enough for the Phillies to gamble on him having an extra year or two left).
He'll be a popular player at the deadline though. FWIW, his 2017 no-trade according to Cot's:
for 2017 season, may block deals to all clubs except Atlanta, Chicago Cubs, Houston, NY Mets, Philadelphia, Seattle, St. Louis, Tampa Bay and Washington
I bet the list is different this year, that is a mix of contenders he'd be willing to play for and teams that wouldn't have been in a position to get him, but of course it doesn't matter, what matters is that he has some control, and that he probably would come back. St. Louis is the other team that would worry me the most on that list since his wife is from Missouri and their foundation is active there, but they also sold their mansion (and foundation remains active in Philly too).