See my response to the same question here: 🚀 Announcement: identity.ic0.app & identity.internetcomputer.org → id.ai (Internet Identity 2.0) - #53 by sea-snake
No, every “identity” from II 1.0 can be upgraded to 2.0, where each retain their anchor number.
A new power-user feature in II 2.0 when signing into a dapp is the “Enable multiple account” toggle, here you can create multiple “accounts” for a particular dapp within a single “identity”. This could be used for example to maintain multiple Oisy wallet addresses within a single identity.
This feature has been added to II 2.0 to resolve the past challenge users experience that had many identity numbers written down just because they needed multiple accounts for a particular dapp.
