The short_open_tag option hasn't been removed, it still exists in PHP 7 (https://github.com/php/php-src/blob/master/php.ini-production#L202 and https://github.com/php/php-src/blob/7aa7627172c11979ec45c2db85f99182812ee59d/main/main.c#L514).

The only thing that changed is <?= works when short_open_tag is on/off. It's still perfectly acceptable to use <? if short_open_tag is set to 1/true/on.