With 14,000+ player's anticipated for 17-18 the AMT of growth from two years ago is something most could have not predicted.
With more MLS sides and residence program gearing up the league will continue to grow until the full convert to single age groups. Might take 1-2 more seasons for the u16/17 & 18/19.
u11 is what heard is a possibility going forward as the start and u18 as the end as before. After that expansion will level off maybe 25k or so by 19-20', DA is likely to remain top of pyramid as long as the MLS clubs continue to support.