I've found this screenshot on Reddit:
Here is a comment from giszmo on the same thread:
Yes, as we said again and again, we are working on a segwit release (under the lead of Sergey Lappo) and I just got permission to share some insights what our main road blocks are.
We support many account types and Mycelium has many features none of our current devs ever used for any real world purpose. We currently also lack Trezor Model T and Ledger Nano S to test with (we will shortly get those). How does SegWit play together with our local trader platform? How about [Shamir's Secret Sharing](
https://en.wikipedia.org/wiki/Shamir's_Secret_Sharing) (yes, Mycelium supports that. I don't know exactly how but I guess we should make sure not to break it in case any user has his fortune in this) or BitId (we know that for bech32, message signing is not well defined).
So, for the simplest of cases of creating a new HD wallet, SegWit works. I could record a demo or show your the transactions we created with our tests.
With Trezor One we ran into a UI issue that is quite interesting: Our approach is a mixed mode account. That means your receiving address will change from legacy to segwit compatibility with optional segwit native. (Terminology is another topic. Power users would maybe want to see bech32, BIP84/49/44, P2SH segwit, P2WKH_P2SH or something like that.) So when in a payment situation you can present your bech32 address to the payer and if his wallet doesn't recognize it, you can switch to p2sh with a simple click, without having to switch to a different account. Also when you pay a bech32 address, your change will go to a bech32 address to get more privacy. (If change should go to a legacy address when paying a legacy address is still up to debate. I think the current state is that it would go to p2sh instead.) Anyway, account mixing raises compatibility and standardization concerns. Trezor for example handles your bech32 account as a completely separate account from your legacy account. I can spend in mixed mode or from trezor's perspective from several accounts at a time but it gets confused about the change output and that has some scary consequences for Trezor users: If you spend from one account and the change goes into another of your accounts, the trezor will ask the user to confirm **sending** the change. It does indicate that the change would get sent to the trezor again but when paying $12 with my Trezor I get scared when I have to confirm sending $12000 to another address that I have never seen before even if it says "Trezor #1" below the address. So ... we have to see if Trezor has a good solution for that, how keepkey and Ledger deal with this, if we should reduce privacy on hardware wallets to keep support manageable, if we provide mixed mode as an opt-in for the more techy users etc.
So yes, we are working on it and we probably could release it shortly but to avoid scary moments for certain users we would probably have to polish the release a bit. We still have to test all features with the release candidate. And then there is code reviewing. It's +8500-5300 lines of code to review.
And about the address scheme that will be used:
bc1 addresses will be part of the initial segwit release. your default receiving address will switch from legacy to p2sh and you can switch it manually to bech32.
https://www.reddit.com/r/Bitcoin/comments/9omnv4/mycelium_wallet_will_finally_get_segwit_this/e7vmje6/
