I suppose it depends on the goal of your IO teams. Personally, our IO6 has zer0 intention of going to Worlds. Most of my girls won't have a tuck, never mind a full. And ask me how much I care? As an international team in a small market, we've had to adapt. I coach primarily 18+ athletes, they have no choice but to be IO6. If I could be IO4, I would. We've accepted our lack of tumbling, and worked VERY hard to over come the points lost in that area by having solid stunts, choreo etc.
I have little sympathy of any IO teams in the USA. Obviously you can field these teams. Other countries simply are not there yet. And now, with this age grid change, they've put us behind significantly, in my opinion, because we don't have the athlete pool to creat a solid team of 24 lv5 or 6 athletes who are 17+. Of all the programs and teams in my city, I think I could make a team of about 15-18 who could max level 5 tumbling.
The USASF needs to stop looking at everything as so US centric. There are other teams out there, who do want to compete, but for a little while, we'll need a little help until our talent base comes even *close* to that of the USA.