No, of course not, it definitly cant replace regular sparring and mma is mixed martial arts, so its like 3,4,5,6 martial arts in one, it definitly has an advantage over a single art such as wing chun. Of course im no professional or hardcore fighter, the most I take is classes, maybe a few spars now and then with friends, however it doesnt replace the fact that wing chun isnt something people should take likely

also vanchild the reason why wing chun isnt really well represented in mma leagues especially the ufc is because unlike muay thai or boxing it doesnt have a history of organized competetive fighting. TKD you use body padding and headgear in fights and not allowed to punch to the face, and alot of them you can't really "fight" like you do in kickboxing and whatever, wing chun is the same. However, as of now there are people starting to use wingchun in serious organized competitions, and there should be a few entering, I think there was one steven something in the euro mma league.

Also in the past wing chun practitioners complained the the MMA rules prevented them from using many of their favorite techniques and as such didnt go because they would have disadvantage against other ones who could go all out with their techniques, however, now that the rules have evolved and wing chun people have adapted their attacking style to the rules they can use wing chun as a striking style in MMA effieciently, of course they will have to learn grappling and ground work, but so do other striking style users.