Which I'd quickly translate as "There's a rumor going around it [Ba'almon] is a Demon Lord Digimon given a different form".
And for the sake of comparison, here's a bit from Babamon's entry:
Which quickly translates to "It's rumored that a Rosemon was put under a curse and as a result took this form".
So needless to say, Ba'almon's entry does resemble Babamon's entry far more than Jokermon's, and since we have have multiple cases of Digimon taking different forms, I'm pretty sure that if Jokermon was supposed to be just a Piemon in a different shape, they'd actually write that there. Meaning that year, Jokermon is indeed just a related species (kinda like one could argue V-mon is implied to have decended from V-dramon, but not quite), not a variant or a different form.