Threads created from messages don't automatically add the OP

Reproduction steps

Set up two accounts
On account 1, send a message in a text channel
On account 2, start a thread from that post

Expected behaviour

The thread should start with two users included, the OP and the thread creator. On Discord, the OP is actually pinged when a thread is created from their message.

Actual behaviour

The thread starts only with the thread creator. If the thread creator does not additionally ping the OP, the OP never receives any sort of notification that the thread has been created.

Build information

Canary Desktop 2026.1018.183012, Web 2026.1018.183012, Linux 7.2.10-200.fc44.x86_64 (x64), Electron 44.4.1, Chrome 152.0.7977.78, Node 24.21.0, Locale en-US

Platform

macOS, Windows, Linux, Web