I'd say yes, given the time that has passed - it's fine. Though be clear it's a fan remake, so you don't confuse other people who played it.
I will add though, that the game thread here on F95 is owned by the developer. While they may have not updated Patreon since Aug-2020 - they were still using the F95 forums until Feb-2021 (but not since).
The big question would be how much of the original game you would use.
From what I can see, it's a HTML game with a few cropped photos taken from other porn images/videos. Though there are some pretty unique (and very well done) hand drawn images too.
The existing images should be pretty easy to grab direct out of the game's directory (or the image pack) - as should the story/script. Though finding matching images for "your" future content may be a bit more difficult, depending on how consistent the original author was about the actors/models used in the current images and how much new "hand drawn" art any future development might need.
You could "show willing", by using images YOU'VE picked to replace the originals... Though it's reasonably likely that the original author probably didn't have rights to the porn images anyway (I'm guessing of course).
You could try contacting the original author. Just because they haven't updated the Patreon in a long while, doesn't necessarily mean they won't read an email notification that they've received a Patreon DM/PM. Of course, sending a private message via Patreon often requires that you have at least been a subscriber in the past (or are currently)... so you may need to pay for the privilege of them ignoring you trying to reach out to speak to them. But if you're keen enough to continue developing the game, you should be keen enough to pay one month's worth of Patreon subscription (if needed) - even if it's ultimately wasted.
You might also consider just PM'ing them here on F95. Again, just because they haven't been active since February doesn't mean they haven't got email notifications switched on for new conversations.
Some very negative speculation. Avoid if the Xmas period already lowers your mood.
... and not to be too harsh about it, but they went quiet during the peak period of a global pandemic.
Edit: ... and if something bad did happen... we don't need to know. That would be a private family matter, especially at this time of year. If you do know something, please DON'T share unless it's good news
Realistically, F95 is partly a pirate site. Whilst we'll generally urge caution... you're asking a bunch of people who regularly download a lot of author's paid content. So consider any answer somewhat biased.