Now granted, I haven’t worked with PHP in one heck of a long time (although that’s purely due to lack of opportunity… I get the warm fuzzies with v7+), but doesn’t bad stuff randomly happen if `<?php` isn’t at the very beginning of the first line?

At the very least, a quick boo through some pretty vintage files of mine shows that every PHP file starts out without spaces or blank newlines - `<?php` is the very first thing encountered. So clearly there was formatting discipline there, but whether it came down to specific reasoning or not is the real question, and one I cannot clearly recall one way or the other.