As there’s evidence to suggest the '81 crawl was spliced into old prints, I’d lean towards all of the above.
If it is true that the '81 release used existing '77 prints, I’m sort of baffled that it was deemed worthwhile to change the title crawl. It’d be one thing if they had to go through the effort to run new prints anyway, but to put in the work to make such a small change to otherwise ready and usable prints?
Then again, this is George Lucas we’re talking about.