Suzu
The default .bashrc SOURCES the following directory of scripts:
source /usr/share/defaults/etc/profile
When I use FISH by putting exec fish in my .bashrc after the SOURCE line, none of the scripts load/work.
Putting exec fish before the SOURCE line leads some scripts to work, but as I understand it, there is a non-trivial syntax difference between BASH and FISH scripts that means that not all bash scripts will work out-of-box without being re-written in FISH syntax.
Some things like setting the Terminal Window Title seems to work when sourcing the bash scripts, but notifications do not.
Dropping exec fish (and thereby going back to bash with the source'd scripts) leads to the out-of-box terminal experience, complete with awesome Raven notifications.