(a) My impression from some semi-recent discussions here and on the Mastodon Discord is that there's much more momentum for abolishing host-meta support than for abolishing WebFinger.
(b) My stance on handles is that they should not be used for protocol-level identification of actors (since ActivityPub already has IDs). Resolvable? Sure. Permanent? Nah. Let people change their names and configure custom domains without moving their accounts. https://correct.webfinger-canary.fietkau.software/#developers