"New" and "modern". Also, "German Style" is the term I hear a lot, which you may not want to use.

"Explore New Boardgames! Did you know there's been an explosion of creativity over the last few years[*] in boardgame invention? Come learn and play some of the funnest board games you've never heard of."

You could also call it the "Beyond Monopoly" gaming group, though it has the problem of characterizing itself by negation.

[* decades are made of years, so for a sufficiently large definition of "few" this is not actually false]