Summary:
An occupied boat with a chest can be opened without using the shift. This doesn't match the java version where an occupied (e.g. mob) boat cannot be opened without shift and a report about this parity issue has been invalidated for some reason (as a feature request) MC-249423.

Steps to reproduce:

1. Place the boat with chest.
2. Put the mob in the boat with chest.
3. Try opening the boat's inventory without shift.

Observed results:
The inventory of a busy boat opens without using the shift.

Expected results:
The inventory of an occupied boat will only open if the player is in shift.

Video:
Bedrock
Minecraft Preview 2022-03-24 23-02-01.mp4
Java
 Minecraft 22w12a - Singleplayer 2022-03-24 23-01-09.mp4