I remember hearing that homebrew/php was going to be deprecated and migrated to homebrew/core, but I forgot somewhere along the way until I started to update my Brew setup last week. I received a few issues with the automatic homebred-php migration. I am not positive, but I think it had to do with the fact that I had also installed php71-mcrypt. After doing some research, realized that php-mcrypt and other extensions that were optional with homebrew/php are included in the homebrew/core version of PHP.