Gohan says it's "different" not stronger, but he doesn't get any more specific than that, so unclear.
That said, I imagine that it's a Controlled version of his INITIAL Super Saiyan from the Broly movie, not his Legendary Super Saiyan form.
Because, as much as I hate to say it, Legendary Super Saiyan doens't exist in modern canon as an actual official form. Kale's is called SSJ (Berserk), Broly's is Super Saiyan (Full Power). Hell, we're even talking now about how Ikari seems to kinda sorta be involved in his version of SSJ. And unlike Z Broly, who could transform and moderate his forms at will (See Second Coming, the SSJ Form he used when he was given a Control Crown, etc.), these new generation LSSJs can't transform at will and have none of the traits the original one had outside of green hair (which wasn't even intended in DBS Broly and actually added in after, DBS Broly was just going to have an abnormally strong SSJ form, which you can see in basically every colored page of the DBS Manga with SSJ Broly in it-Yellow hair instead of just green), and an ever evolving power.
It's very likely, to me, that the term LSSJ was phased out in favor of maintaining the allure of Goku becoming the Legend on Namek, and Broly as some freak of nature (fitting his new Tarzan like backstory), that has nothing at all to do with the Mythos of the Saiyans. ESPECIALLY when you realize that apparently the Original Super Saiyan (Yamoshi) then became a wandering Spirit to find the Super Saiyan God (Goku). Meaning Greenie doesn't exist in any of the "Super" Saiyan Tales and Folklore compared to Toei/GT.