bracketed notes not mirrored in tablature

The short answer is no, Dorico doesn’t mirror this particular property automatically between notation and tablature.

It’s a design decision. Where we believe it is useful to do so, we make it possible to set things separately – whether that’s in the full score or the instrumental part, or in notation or tablature – to provide maximum flexibility. We encountered scores where notes were parenthesised in the tab but not in the notation and vice versa, so in order to accommodate that we made it possible to set these things independently.