Meh. If he finishes then great. If not then great. I will know that I tried my best to bring back the game and will be able to work on something fresh with peace of mind.This is my personal opinion without proof. I suspect the original dev of LOI is just being petty and will drop his version of the game if Sihil didn't go on making his own version.
I would personally like to have the characters of LOI appears as cameo but have a story totally separated from the original LOI. Multi dimension/timeline is quite common so i think Sihil can just to ahead and do his version. I doubt the original Dev can do much even if those characters appear. I dont think it will occur any copyright issues too, given that there is no legal documents signed or any of the characters have been copyrighted.
I'll probably only bring Zel back. The rest of the characters if I ever get to make a Lord of Imagination-adjacent game will at least look different.