I can't really answer on HMBA's commitment to Washington Township Park, but I can offer some info based on DINO experiences.
We stopped MTB racing there after a 2011 weather-related cancellation and ongoing difficulties with the management. The good news is management has changed completely since then; they are quite good to work with now. We held a 2015 Trail Run there.
However, there isn't really enough quantity of trails to make a race course without using a lot of pavement, and there are countless cut-throughs, making race marking very hard. Lots of eroded places makes it for a very difficult for a beginner-friendly MTB race.
I think what's needed is a few committed local volunteers working with park management to do some re-design. I don't see it ever having more than a 4-5 mile useable loop of trails due to the size, but we definitely support the local trails which serve to introduce new people to the sport.