For those waiting on Cave Story+ 2.0 update please standby. It was approved by NOA+NOE/scheduled for 9.15. We're checking with @Nintendo now— Nicalis, Inc. (@nicalis) September 16, 2017
No word on why the update hasn't been pushed out yet, and it seems Nicalis is in the dark as well. When the update goes live or we get another update from Nicalis, we'll be sure to share.