We should consider the angle of the stumbling block. The Church has a long history of baptizing pagan symbols, like logos, Christmas trees, and the ankh, but most people in the pews aren’t aware of that history. It’s not common knowledge. So you could end up in this awkward spot where you’re technically correct about the history, but also accidentally making someone’s faith experience bumpier than it needs to be.
If you’re the type who enjoys a good ‘actually, about Coptic Christianity’ conversation, wearing one could work as a small evangelism opportunity. Adding a cross element, as in the Coptic version, does make the whole thing a bit less ambiguous, too.
The symbolism of life and eternal life lines up fine with Christian teaching. The ancient Egyptian belief about confessing before God and having your heart judged fits with what we believe, too. Nothing about it contradicts Jesus’s teachings. The Coptic church uses the ankh in the same way other churches use the Roman cross to identify their faith, which says something about its legitimacy.
Some stuff God does might look like what foreign religions describe, but those are fake idols with no real power. The ankh represented one of those false gods. Early believers made an error incorporating it, the same mistake young Christians make today when they casually adopt terms like karma or zen into their vocabulary. Just stick with symbols that don’t carry that baggage.