Base on https://www.watch.impress.co.jp/docs/news/1505718.html, non-registered IC cards such as SUICA, PASMO, Monorail SUICA and Rinkai SUICA will not be sold until the IC shortage is resolved. Non-registered SUICA will continue to be sold by JR East in some? Aomori / Morioka, Akita areas where they just recently started accepting SUICA via the Super SUICA (or SUICA 2.0) cloud network.

If you have newer iPhone / Apple Watch models that support mobile SUICA, just add SUICA to your wallet, but don't forget to set it as Express Transit Card so you don't have to keep authenticating like you do with Apple Pay before going through the gates.