True and for everyone's benefit going forward this is an upstream Google/AOSP issue.

While GrapheneOS ships the AOSP keyboard as a requirement for system functionality this is not a GrapheneOS issue owing to the fact other options are available to users.

Gboard is unfortunately the reason why AOSP keyboard isn't actively developed. They split off Google Keyboard from being an enhanced fork of AOSP keyboard and developed it into Gboard.

So while GOS Keyboard is AOSP keyboard with minor modifications such as disabling learning based on your typing by default for improved privacy. For those maintaining a 'degoogled' approach, FlorisBoard is what we eventually plan to use instead of AOSP keyboard. However FlorisBoard isn't at version 1 yet and is missing some basic features despite having advanced stuff like swipe typing working already. Recent developments will see progress regards predictions and NLP integration hopefully soon though.