No, the “no romantic attachments” rule didn’t appear explicitly until Attack of the Clones, although arguably a more nebulous form of this rule was hinted at in Phantom Menace. But the OT definitely never even considered the idea of “no romantic attachments” as a possibility. The pre-Prequel EU of course never considered this idea either, and thus we had Jedi getting involved in romance like everyone else (e.g. Mara Jade, etc.).
You can argue further (as you point out) that the OT not only doesn’t have this rule, it outright contradicts this rule, since we hear that Anakin had offspring and the movies never indicate this was in any way weird or not expected of a Jedi.
Also, having offspring is possible without romantic attachments. The Jedi rule is specifically about romantic attachments. Arguably, some species that say, reproduces by laying eggs and then just abandoning them (as is done by many species on Earth) would be allowed to be a Jedi AND have kids.
There have been a couple of in-depth discussions about this issue in previous threads in this forum.
The general consensus around here is probably that romantic attachments were allowed until George Lucas decided to inject some Romeo and Juliet into his love story, because he didn’t know how to write a love story. I mostly agree with this sentiment, but consider it a bit too reductive, since arguably the “no romantic attachment rule” could be considered a logical consequence of the Jedi’s general dislike of emotional attachments, which was implied (if somewhat muddled) in The Phantom Menace when they bring up Anakin’s fear of losing his mom.
I’d agree with pretty much all of that, and especially the part in bold. Even today, barring “romantic attachments” etc in AOTC comes across as an outlier, something written to be “Romeo & Juliet” or rebellious love as you posted, and just not executed very well at all. Going from learning about this “rule” to actually seeing them “fall in love”, to getting married by the end of the film, despite his genocidal tendencies, raises other questions about the characters and story being told.
It isn’t difficult to see why other writers (whether in EU, legends, canon or whatever), have basically ignored this
“forbidden romantic attachments” rule introduced in AOTC, or simply written around it.
Sideburns of BoShek said:
I haven’t read “Light Of The Jedi”, or much of The High Republic, set 500 BBY to 100 BBY, but in there are apparently Jedi who fall in love, have intimate relationships, and also form emotional attachments:-
'For as different as they might initially seem, Avar [Kriss] and Elzar [Mann] are presented as extremely close friends in the novel, having grown up as fellow younglings, Padawans, Knights, and eventually by the time of the book’s end, Masters of the Order. They go everywhere together, on missions or on downtime. They are compassionate for each other, clearly. Their connection together allows them, as Jedi, to do spectacular things with the Force multiple times in the novel, building on Avar’s own unique ability to connect her fellow Jedi through the Force in powerful acts of sensitivity. One of the last scenes in Light between the two confirms something that felt keenly obvious in looking at their relationship throughout: at one point, as younger Jedi, Avar and Elzar were romantically entwined, before choosing to amicably separate to focus on their studies as apprentices of the Force.
Two Jedi. Two Jedi who loved each other. Who still do. Who are not just good friends, but deeply intimate with each other in a way that goes beyond friendship. Two Jedi who are, by very much any definition of the word, still emotionally attached to each other.’
Another “+” for the High Republic.