There are plenty of new CoD sets being released. I admit, Mega could try a little harder to list them all on their site properly, but there are definitely still new ones coming out. Even though some of the sets aren't visible on-site, you can still see the figs they come with:
https://callofduty.megaconstrux.com/en-us/figures
https://www.megabrands.com/en-us/constr ... ll-of-duty
Given all of the painted parts and new moulds on show in these sets, and other new ones that can be found elsewhere online, I think it's safe to say Mega are putting more effort into the line, not less.