Your assumption is based off outdated information. 0.3 was sara's last update. 0.4 was Caroline (sara not included in poll as successive updates cannot have same characters), 0.5 Linda (sara present in poll), 0.6 again Caroline (sara again present in poll), 0.7 is gonna be sara because Icstor decided not to include Caroline or Linda as they would've been voted for again. and finally 0.8 again is for Linda.
If anything his patreon numbers won't be increasing/decreasing by much because most of them are already waiting for Linda's update. even if the patreon numbers increase it will be because of the anticipation of the Mommy update. Sara has a very minute following, hence he might have a lot more freedom and chances to delay 0.7.
But at the end of the day, the game is awesome and he'll give a worthy update.