It may; but FTTRC is in firm standing as far as being THE official, recognized caretakers of the Beacon trail network. As far as the city Parks Dept. and the stakeholder private landowners are concerned, they are in the driver's seat as far as stewardship of the trails. With the countless hours the club puts in, I'd like to think they are going to have the ear of any official body more than any other user group when it comes to trail access there. This is also a not-so-subtle plug to JOIN the FTTRC if you have not already done so; and get involved in the trail-building/maintenance days. Be a part of the "countless volunteer hours" that carries the weight of our voices being heard.
Now, specifically, as far as *****r's subdivision and how it will impact (had to type short earlier, so I can go into more detail now): Yes the development will cut into a chunk of trail on the Ezzy side - - if I'm understanding correctly where it is, it will wipe out part of the flowy turns going down off the towers toward Ezzy (Trail 20 I read). Too bad because that's one of the most fun XC trails on the whole hill, IMO. The upside, if there is one, is that section of trail can be re-routed and still retain much of the character that it has always had - - just moved over some.
As far as traffic, yes the dog-walkers and casual users will go up significantly and that will probably cause some conflicts; but actual enthusiast traffic (as far as more bikers clogging the trails) - - I don't forsee so much of an increase as to be that noticeable. It's some moderately challenging terrain and the novelty of all the climbing and descending will wear thin with the more casual users eventually.
This link will give you a better idea of just where it will sit on the northwest face of the hill:
http://beaconhillspokane.com/map.
I'm actually more concerned about what's going to happen to the top of the downhill, since that is owned by a developer and the subdivision is barking up the backside of that right now.