Koguma did say they wanted to put the innkeeper as a possibility in their latest update some time ago. Don't remember when and if they actually made it though.
They didn't, you can check the update history on their ci-en and DLsite, the version posted here recently is the last one. Any plans for this game were put on an indefinite hiatus as development focused on their new game.
Last post mentioning the innkeeper went over how the dev was considering adding her as a bonus ending bit, with one pose for just one of the male characters (Takashi, the 0/2 guy), because adding her normally would mean at least 6 new animations (12 if you could posses her too). In the end, you can find his comments under that post, with more recent dates, apologising to people asking when/if the inkeeper scene is coming.