Disney's first adult novel of The High Republic initiative reveals some surprising new reasons why a Jedi might change their lightsaber in Star Wars. Set 200 years before Star Wars: Episode I - The Phantom Menace, the Jedi of the High Republic era represent the Order at its peak. These are not the same Jedi seen in the prequels, whose power and Force connection had been diminished by their own fear, and were also blind to what was truly happening until it was too late. Instead, these are all-powerful Jedi Knights and Masters, with deep links to the Force, and that extends to their lightsabers.
The Star Wars movies haven't shown much in terms of a Jedi getting a new lightsabers. When they have done, the reasoning has been easy enough to understand. Anakin made his blue lightsaber (the Skywalker saber), after his first was destroyed, and then changed to the red lightsaber he wielded as Darth Vader. His son, Luke, inherited the Skywalker lightsaber, and only made a new, green one after losing it on Bespin (though Star Wars canon has since revealed he had a yellow lightsaber in between). In Star Wars: The Rise of Skywalker, the Skywalker lightsaber is buried at the Lars homestead on Tatooine, and Rey unveils a new, yellow lightsaber, which is to represent her new path.
Generally, then, there's been a clear need for or deep significance to a Jedi changing their lightsaber, but The High Republic is shifting that. In Charles Soule's book Light of the Jedi, there is a new list of reasons given as to why a Jedi might change their lightsaber, which is apparently far more commonplace than what was shown from the timeline of the prequels onwards. In a passage with the Jedi Te'Ami, her lightsaber is revealed to be in bad shape, suffering from a lot of scratches and gouges and having had to be welded back together in parts. It still works, so she refuses to change it, but does not that it would be possible:
"Could Te'Ami have refreshed the blade, if she wanted to? Absolutely. Want Jedi changed their hilts regularly, whether due to adjustments to fighting techniques, technological innovations, or even, on occasion, just ... style. Aesthetics. Fashion, you could call it."
All of these reasons for a Jedi changing their lightsaber help provide a fascinating new look into how the Order operated at this time. Of them, the first is the most understandable, and one there is some basis for in the prequel-era. Count Dooku's lightsaber famously went against the grain of what was the convention at the time, as he designed it to have a curved lightsaber that was specifically tailored to lightsaber-vs-lightsaber combat, a telling move given this was a time when the Sith were supposedly gone. With at least seven known lightsaber combat forms in Star Wars canon (and perhaps more in the High Republic time), then it would make sense for Jedi to adapt to new techniques.
The other reasons are perhaps a little more surprising. Not a huge amount has been shown with regards to technical differences in lightsabers - while there may be differences in hilt and blade color, they often tend to function the same way. But, like how Rey's emitter on her yellow lightsaber was different - using a thumb switch rather than a button - than it's not too difficult to imagine other such technical changes as the technology changed. It is harder to imagine many Jedi from the Star Wars movies subscribing to fashions or prioritizing aesthetics in the lightsabers, but it does fit more with what's already been revealed of the Jedi Order during the High Republic.
There's a greater sense of style to them - when attending ceremonial Republic events, they're adorned with fancy cloaks (not unlike, say, the Kingsguard from Game of Thrones) - and also much more freedom too, allowing for different explorations and uses of the Force. Even just from the book covers and marketing materials, there's a clear array of lightsaber designs - some double-bladed, others crossguard and so on. This was all mostly gone by the Star Wars prequels, with the Jedi more dogmatic and following Yoda's way, but the High Republic was a different time, and so it's understandable how the Jedi viewed their lightsabers would be different too.
