You're one of those glass half empty kinda guys, aren't you?
I look at it this way. Bendis himself didn't want his LSH to be a reboot. It being a reboot wasn't particularly popular with a lot of fans so there's no upside to sticking with, presumably, Didio's decision to retcon away all previous LSHs when they could easily co-exist as previous incarnations of the team from alternate futures, which Bendis has already established in his LSH run. Furthermore, DC currently has a stated policy of "Everything Happened" in terms of its continuity, which actually means they're just not going to get too specific about the exact details so that fans can fill in the blanks however they want. Clark has a Legion Flight Ring at his Fortress of Solitude. Clark was a fixture of the LSH for decades and removing him from their history was deeply unpopular and caused countless problems for the franchise long-term.
So, what possible reason would Bendis have for not acknowledging that Clark was once part of an earlier incarnation of the LSH at this point? How would that help make Clark's story more interesting? Or Jon's? Or Kara's?
DC has been around and around the whole "All those stories never happened, but these ones did" thing before and it didn't work out very well for them, particularly in regards to the Legion. And Bendis said so when his LSH was first announced. He specifically said that it was
not going to invalidate any of the wonderful stuff that Waid, Giffen, or Levitz had done, which is why he planned to set in the 32nd Century.
But, sure, if you want to believe it's just Jon's ring and nothing more, go ahead. I, on the other hand, tend to favor the idea that Bendis is offering an olive branch to fans like myself who enjoyed his new LSH, but were miffed that it was yet another reboot.