Yes, but unlike Startpage and Duck Duck Go, Pi-Hole is actually free and open software, so it could just be forked.

True, and that is why I mention it as an example. I believe these online ad industry people will try anything, even something that appears futile to you and I. Last I checked, Pi-Hole does own a trademark application. Presumably whomever acquired it could use this against a fork that tried to use the name.

Having to change the name doesn't seem like an insurmountable obstacle for a fork. (Pi Hole-Origin, Next-Hole, Ice-Weasel-Hole)

Does it seem like those names would not support a trademark suit? Would you have to use the word "Hole" in order to attract users?

> Does it seem like those names would not support a trademark suit?

They're based on real world examples retaining recognizable parts of the original name: Owncloud -> Nexctloud and uBlock -> uBlock Origin.

Of course it's not impossible to get a new name, but it's easier branding-wise staying close to the old one.

My parenthetical suggestions were a joke.

But having to switch names, even to something completely different, would be manageable, I'm sure.