They explained the reasoning in the chat. As you TP out, you can take a small amount of damage without it interrupting the process. The dev was concerned that this could be exploited by using it in the middle of a boss fight to easily escape (most likely by hardcore characters, though he didn’t say this). He acknowledged that it was a poor way of going about it as there are many other ways to do the same thing without it slowing things down for everyone, so they reversed the change.

If you’re interested in hearing the devs reasoning for changes or design philosophy, watching the full version is worth it.