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.