I don't know. I personally I don't believe tickling itself was ever a problem, even in this torture in stocks scenario. First of all, it wasn't too long to truly exhaust someone, was quite dynamic and - especially in case of those more recent festivals - it's not like people were dragged there by force. And form what I've seen, most people rather enjoyed it, saw it as a harmless and fun entertainment and very often volunteered to do it. Even in case of Stimulating Feet - putting all controversies aside - many visitors decided to try it, even if they knew they were going to be tickled. And in case of Canelli, it didn't stop because they were banned, but rather the city stopped organizing this festival at all, so they stopped coming. I think the backlash was more about the footage appearing on fetish and porn sites.
Having said that, I have a feeling that many organisers are now more careful in regards to what they allow to happen during those festivals. It is true that nowadays people are less "tolerant and open" to many things, and can be more easily offended. And this change of attitude has of course some positive aspects (people are more careful to avoid potentially dangerous situations), as well as some negative (some people have no trust at all and see everything as problematic). And renfaire tickling might be it - after all it is about physical contact, and I imagine many people might not be comfortable with it. On the other hand, if no one was forced to do it, and only volunteers were locked in the stocks and tickled, then I'm not sure who would have problem with this. But since you can't predict how people would react, and that a video can be all over in the internet in the matters of seconds, the vendors might be simply afraid to do it.
So I think people would be willing to participate in it, the problem is that people who are vendors on those festivals might be afraid to recreate this activity. But this is just my opinion, I'm not saying I'm correct in my judgment