If there is, I can’t find it. It’s also not listed as a new user limitation here:
In any case, the likes per post ratio on that forum is >1 so they don’t seem to have a problem of users not liking enough. But I still see no reason to reduce the number of likes per user (even and especially new users, if that is really possible). It turns people off and I don’t understand their anti-spam argument. In fact, limiting likes like that even does damage because it forces people (like yourself) to create an entire post in order to say “thank you” or “me too”. Preventing that kind of noise is another important function of the 
button.
But nevermind. My comment was just meant as an aside as it doesn’t solve your issue. The only think I could say in relation to your actual question/suggestion is that with the default setting of 50 likes per day, that modal that is annoying you should only appear in extremely rare situations.