Yes, a minority enforced soft fork can cause a permanent chain split.

If hypothetically the entire network had been using RDTS rules and then someone made a software change that removed the mandatory signaling, this would remove a restriction and would be a hard fork. Only nodes that upgraded to this new software would be able to follow along.

bitcoin

bitcoin_beginners

What’s the difference between a soft fork, a hard fork, and a chain split?

Murch

Yes, a minority enforced soft fork can cause a permanent chain split.

If hypothetically the entire network had been using RDTS rules and then someone made a software change that removed the mandatory signaling, this would remove a restriction and would be a hard fork. Only nodes that upgraded to this new software would be able to follow along.