no ! pacman no write in home, and you can run pacman -Fx "bashrc"
if you want changes of your .pacnew, you can create your git repo:
create repo
mkdir ~/.local/share/pacnew.git/
cd ~/.local/share/pacnew.git/; git init
#git push # in private repo if you want web diff
after all update, before merge, save change in local repo
cd ~/.local/share/pacnew.git/
cp -f $(find /etc -name "*.pacnew") ~/.local/share/pacnew.git/
git add -A
git commit -am "$(date) pacman update"
git push # in private repo if you want web diff
after a rotation, we have the upstream difference between 2 โpacnewโ