When people see this, they see AI features. When I see this, I see the death of CalDAV: https://www.macrumors.com/2025/05/23/apple-calendar-app-job-posting/
Apple Calendar App Revamp Confirmed by Job Posting

A new Apple job listing has provided more evidence that the company is working on a major overhaul of its Calendar app. A senior software engineer...

MacRumors
@helge slowly but surely silicon valley is gonna push me into self hosting every service I use for my friends and family. Hope they like using a VPN because I ain't trusting my firewall to that 🤣
@axiixc That's something you can still do today for calendars and email (thanks to CalDAV, IMAP4). But Notes and Reminders are examples on how we are going to loose this capability going forward (it's not quite correct, both still kinda support the legacy, open protocols, but not in a full featured way).
Open protocols have primarily been useful to Apple back when it didn't own the market.
@helge @axiixc Yep. I'm hopeful they'll keep support for the open protocols around, since I can't see them leaving enterprise users and others without an upgrade path. It'll probably be one less service from iCloud I can access from Thunderbird on my Linux box though.