Almost but not quite. All they did was plop in a copy of the GPL. That by itself doesn't mean anything. They also need to actually grant those permissions. There's a "How To" document at https://www.gnu.org/licenses/gpl-howto.html that covers adding the appropriate things to their program. But a free-standing copy of the GPL, without any further information as to what it actually applies to, means nothing. ("Oh, I only meant for it to apply to the README, not the program...") So they follow that page and add stuff into each file.