My Fluance speakers reconnect automatically, and don't need to be paired again.
However, there is a bug where the overall volume level gradually drops over time, and even at maximum gain on the speakers, it's very soft. Deleting and re-establishing the pairing restores normal operation.
Have yet to figure out whether it's the Mac, or the speakers at fault.
Forgot to mention that the pair will sometimes negotiate an SBC connection, when aptX is supported and works most of the time.
Not speakers but a JABRA Bluetooth headset. And it's a major nuisance as Apple's Bluetooth stack is absolutely abysmal. A major PITA. Horrific. Atrocious. About as reliable as a faulty memory stick. More bugs than you can shake a stick at. You get the picture.
I did not have to re-pair them but I did have to reconnect them every time I rebooted my iMac. Most of the time this worked great and reliably, but then with 10.14 Apple somehow modified its Bluetooth stack with the result that more often than not I had to reboot multiple times because the headset kept disconnecting after a few seconds. Only a carefully orchestrated act of reboots and unplugging the headset base eventually resulted in a working headset. That is until at some random time macOS decided to go full retard again and decided it would be a fun game to disconnect from the headset every few seconds again. This was seemingly fixed with Catalina until 10.15.3 came along, at which point things turned ugly again and the old problems returned with a vengeance. This time the procedure to get it going was slightly different as I did not have to restart the headset anymore but only the iMac, sometimes 4-5x in a row in order to get a stable Bluetooth connection. Granted, it happened much less frequently than with Mojave but still often enough to be a major nuisance. I have since given up and connected the headset via USB. I've lost the ability to quickly pair it with my MacBook but since I haven't done that in a while it's not a big deal.
TLDR; macOS's Bluetooth stack is the worst piece of software on this planet.
Latest results: after using the speakers for a couple of weeks they have STOPPED NEEDING TO BE PAIRED after I shut down the iMac or reboot either. I wish I could tell you why this wasn't the case earlier, but I haven't a clue. Anyway, never turning off the speakers who are cabled to the iMac headphones plug, w the green lite on the front of the speakers(pc/aux mode), and the speakers are working fine after rebooting or restarting. One other thing, these speakers have incredible sound.