Also, the PHP tags (<?echo...) in the examples suggest that they are using an (very) old PHP version which might contains unpatched security holes.
The only thing that's changed is that while in older versions the <?= shorthand was also controlled by the short_open_tags ini option, it's now permanently enabled.
No.
http://php.net/manual/en/ini.core.php#ini.short-open-tag
$ cat test.php
<? var_dump(PHP_VERSION); ?>
$ php test.php
string(5) "7.0.9"
$
Please, accept my apologies. :)