Everyone should attend a junior or college event to see just how far junior and quasi-professionals hit the ball.
The answer is 'Yes' for juniors as to 'distance'. Not sure about the scoring part of that equation but when officials see juniors rip it 300 yards routinely then they have to think about adding yardage ...... what with the potential for bothersome scoring issues. Your can only narrow the fairways and tuck pins so much.
Without wind, inland courses are seen as defenseless in the struggle against lower scores....and so the 'beat' of longer continues. It is not unknown for PGA officials to visit your course and upon first visit by non-architect type, make suggestions for longer tees here, here, and here. Unfortunately, club officials almost automatically give weight to such opinions.
Oakland Hills will undergo additional changes after 04 Ryder Cup. New tee will be added at the TOC (14th I believe) even at a 'windy' links course.
To top it off, even local players can hit pretty far and although under par scores are not routine by any means, it adds pressure to lengthening when members stand up and say, oh yeah, I add x iron into the green (insert 8,9,PW,SW for x). Even though they do not have 'plus' handicap...
Lenthening will continue for at least the next few years.
If your want your strategy to hold up (on an inland course) & customer even dreams of a 'national' mens event, I don't see why you wouldn't consider 8000 yards or more when laying out a course. You wouldn't place the tees back there now but should have some idea and space to move them back.
Anyway, my plan is to attend a college event (with ranked national schools) this weekend. Local school has Adidas (Taylormade) as a 'sponsor'. Quasi-pros have almost unlimited access to latest drivers, etc. It should be fun watching the drives.