It has been a bit for me, but I did not recall that.
I was not sure if they changed distribution or anything and did not have the rights.
Although it is Sam Raimi. In Evil Dead 2 they reshot parts of Evil Dead 1 to sort of retcon it but indicate the same things that happened in a different way. So there is that I guess, although I think Raimi just did the first Darkman, I think.
Movies have odd things with rights though. Return of the Living Dead 2 is one that always springs to mind, as it lost the rights to the soundtrack along the way. So instead of punk rock and metal it went to like elevator music in one DVD release, which was pretty wild to me.
Vosloo took over in Darkman 2 and 3 and both were direct to video.
Despite being direct to video they weren't awful to watch. As to switching Liam to Vosloo for flashbacks, well that way they only pay Vosloo.
Also if memory serves we were going to get Die Darkman Die first but the actor that played Durant became available so they gave us Return of Durant first instead.