Frankly, when they did the "face update" some time ago I'm surprised they didn't offer even a single, one-time chance to change your appearance if you didn't like what they did to the face you chose when it looked different. I shouldn't be surprised, but I still was.
If Bungie isn't going to let you change your character's appearance even when [b]they[/b] make changes to it that you don't want, then there's no way they're going to implement a system to let you adjust it whenever you want.
This. So much this. My warlock's now got RBF. He doesn't look the same as when I created him and it bugs me.
I'm reminded of monster hunter world here- Capcom allowed us to have a couple of free character edit vouchers, and you can buy them if you need more.
If this ended up being the case here- except with silver or even dust- I'd still be happy. Because I'd rather have the chance to change my character's look than possibly delete them like some of my friends have.