I would definitely not release it - in particular, not before we crack the metals problem. Now, once we have that, then I would suggest producing it, then shaping it into a convenient ration form and trading it.
So what happens if, say, the 504 get the info and the warning? Well, now they've got a bright idea - produce the stuff and sell it on to others without warning them. If everyone gets the info and the warning, then slaver groups can cheerfully reserve the tasty and safe stuff for them and feed their slaves the sap.
No, release is irresponsible at the current point - and even when we crack it, I'd trade the stuff in a safe form for stuff we can use to continue to expand, feeding and sheltering an ever-increasing population.
@Academia Nut, how viable is the sap in the current form for the organic raw material needed for the medical tech?