Inside ECC we’ve agreed that we’d like to stop supporting taddrs. However, there are a lot of tasks that would need to be done first to minimize disruption to the ecosystem and community. Realistically it would probably take about two years, and that’s after we prioritised it as our top priority.
Also, removing support for taddrs isn’t a good way to get third parties (like exchanges and wallets and so forth) to add support for zaddrs. Instead we’re working hard right now to help such parties adding zaddr support — you’ve seen a couple of public announcements already, and stay tuned for more and more wins!
(Oh, I see that Linda also posted an answer to this question. See her answer above, too!)
I predict that Scalable Zcash will not support taddrs, because of technical issues, and because the community doesn’t value endless taddr support highly enough that they want to endanger Scalable Zcash for taddrs. Adding requirements into Scalable Zcash increase the risk that it won’t work (at both technical and business/ecosystem/strategic levels), and adding non-requirements (e.g. “This will not support taddrs.”) increases the chances we’ll succeed.
By the way, I love the PRINCE proposal! https://www.reddit.com/r/zec/comments/c70fzz/privacy_proposal_for_zec_incentives/
That proposal is to start phasing out taddrs now, not by a flag day “On this day it will stop being supported”, which requires massive effort throughout the ecosystem to prepare for, but by instituting a modest fee for using taddrs and a modest bonus for using zaddrs! If the community really wants to see a widespread shift from taddrs to zaddrs over the next couple of years, the PRINCE proposal is — in my opinion — a lot more likely to succeed at that than any other proposal I’ve seen. Somebody oughta ZIP that!
PRINCE would also reduce the disruption of the eventual “Waitaminute Scalable Zcash isn’t going to work with my taddr!?”.