Amtrak bases the coach point valuations on the "value" fare class, which has went up quite a bit over the past few years on the NEC. Right now it appears to be set at $115. For cash purchases, Amtrak competes on price with their "saver" fare class, but that doesn't help for points redemptions as those fares aren't available for points redemptions.
There doesn't appear to be that same distinction with business class on the Northeast Regionals, so when Amtrak sells those at lower cost (to get people who want to pay a bit more but not $115+) those are cheaper redemptions since they only require $89 worth of points instead of $115. (Note that Acela does have saver/value/flexible, so those will still be tied to the higher value fare class.)
Ok got it. So the reason it is not 2500 points anymore is because the "value" fare class has gone up 60%. thereby requiring 4000 points now? Seems like a huge price increase which is why I thought something else may be going on..