Had this discussion elsewhere.
Basically, if Fulham want Dembele back on a standard 6-month loan, a recall is a no go as it is not allowed under League rules.
However, even though Dembele is a contract player, because he is under 20 he could be loaned to Fulham as a youth player. If that was the case, a recall clause can be negotiated.
However, even if he is on a youth loan, and even if Fulham agree to the insertion of a recall clause, under League rules it cannot be triggered with the first 28 days of the loan. That's not the end of the world, obviously, but if Kane were to get injured in that period Dembele would still be out-of-bounds for us no matter what.
Basically, given Fulham's determination to get him back on loan, I suspect a recall is highly unlikely