I've been having this issue for a very very long time since commands are now in the bedrock/pocket edition
Yes, the command feedback was disabled, they no longer pop up when player does the command, but command blocks still shows the feedbacks to the player's chat screen after the command
It's annoying especially when you tried to make command block map
Basically the only command feedbacks that are disabled are from those activated by player chat not those commands activated by command blocks
Executing player in command still shows command feedbacks too
My device probably don't support the command, so yeah, I hate this
Thank you for your report!
However, this issue is Working as Intended.
The sendcommandfeedback gamerule only controls output from commands entered in the user interface. For output from command blocks, use the commandblockoutput gamerule.