I’ve started to see a rising number of posts calling them unlimited 
I guess after printing unlimited and before wrapping them in booster packs, there is no additional step and they remain intact. Once they are printed, they are complete and later released as official cards in packs.
Whereas 1st editions still needed the stamp, thus being “ready” for wrapping at a later point than unlimited, making unlimited first to be physically created in their final form.
But I don’t really know, it’s just a fun topic to think about 
The main theory I’ve read is that Shadowless was a somewhat rushed released to meet the huge demand after 1st Ed immediately sold out, and so in a sense it was the first ‘Unlimited’ print before they actually released the true Unlimited set. Then the other theory I’ve read is they ‘ran out of ink’ for the stamps and that Shadowless were just ‘left over’ 1st Ed cards that weren’t stamped and they got produced as-is. I feel like it could be a combination of both of these factors.
The thing is, WOTC learned from their major mistakes they made with MTG production (the notorious Fallen Empires disaster, etc) and so they were much tighter with print runs initially, especially on a totally new TCG product which even some analysts thought wouldn’t be popular in the West back then (turned out they were very wrong).
Of course over time people realized the differences between all of them them; 1st Ed/Shadowless and the actual Unlimited cards and the value/collectability prospects improved on Shadowless compared to standard Unlimited once the nuances were better understood.
I was thinking in this thread and arrived to a similar conclusion … What you mention is the most accurate name tbh …
- 1st Edition Stamp
- No 1st Edition Stamp
Also concluded that the term “Stampless” is not correct considering that there’re cards with other type of stamps (Expansion Stamp, Event Stamp, etc)
Sites like TCG Collector name these card variant (No 1st Edition) as “Normal” … ironically, this term is more innaccurate than Unlimited considering that there are expansions that are way more difficult to find as Unlimited than in 1st Edition … This is something that happens mostly in Japanese expansions.
