Avoiding stasis doesn't mean everything levels up with you, but the world changes all the time.

That goblin den pestering the village could be
1) Destroyed by someone else.
2) Done with the place after the peasants fled somewhere nicer.
3) Somewhat grown as guys from #1 kept failing.
4) The same as always.

#1 is the boring end, but a common one once people decide to take action (which they did summoning your players, and again since the players didn't come)
#2 is common as well, since people react different to being fed up.
#3 is a middle ground, and the evolution should be coherent. Maybe the den is now three. The goblins got a couple levels under their belts (just a couple, really), upgraded from warriors to fighters if things really evolved. More elaborate fortifications, traps and raiding methods.
#4 happens too, more common to situations where all intelligences involved are similar (wildlife on timespans under thousands of years is here, as well as enmity between States without power to stomp each other and its neighbors)