Without meaning to sound rude, what made you think that the XP-30 was going to have drum tracks in the first place? The only keyboards I know that have them built in the so-called "arranger" keyboards--the department store Casios and Yamahas and the higher-end Rolands and other brands generally used by street performers and one-man lounge acts.
That said, I do believe that the "Drums and Bass" expansion card has a bunch of grooves. My "World" card has a number of useful African drum grooves (but these are sampled; you can't edit them although you can control the tempo). And, as someone else said, the Techno card within the XP has a number of rhythm loops.
I don't find the XP-30's lack of a onboard sequencer to be a flaw. The whole purpose of the XP-30 is to sacrifice the on-board sequencer capabilities already existing in other XP models in favor of a greater sound selection. Personally, I've never found an internal sequencer easy to use or usefulThese days, nearly everyone uses software sequencers, most of which come with usable pre-made drum track sequences.
Jeff in Boston