This is not the first time, and probably it wont be the last time either, for this game to be "abandoned". It is kinda a golden egg for the dev, where he can earn more than enough for his living, and all that by not doing anything. In his best interest is to save that source of income, so it could be expected as the support drop further (bellow 500$ or so) monthly, he could come with a new update just to boost it a little, and repeat/sustain the pattern.
We could argue why he is satisfied to earn just 10-20% of the monthly income he would make otherwise (aka being more reliable hardworking dev who makes one of the better popular games around). His choice, and probably for most here, is/would be to earn less, yet to do nothing, as long as it could be maintained.