The article said they are looking for $1m to $10m in funding. Given the hype and pedigree, I feel they could crowdfund the low end of that trivially.
A few other old time devs have tried reboots of their games (a few point and click adventures, mostly) and they were hyped up beyond belief since they were made by legendary developers and were "bringing back the classics". Then they released and got a few sales from older people wanting to get a taste of youth again, but realizing it's just not the same. Those new games by old devs didn't progress in terms of gameplay, and visually, they were worse because they tried too hard to be "retro" and made things look shoddy and low effort on powerful hardware. When back in the day, artists busted their asses to make things look beautiful on shoddy hardware.
Myst has had a bunch of sequels and remakes, but there's a reason people only care about Myst 1. It was lightning in a bottle and trying to desperately pull the "remember Myst?" card several times gets a bit embarrassing after a while.
If a publisher wants to fund something cheap and niche, maybe a bit of a gamble, it’s too much.
If they want to fund a more fleshed-out title that is likely to succeed with a bit of marketing spend behind it, it’s almost too little.
So I think they might be right, they’re in a weird space that publishers don’t want to look at right now.