Update from @Swanson02 above regarding Monarto's two boys; Chad and Ruka, who are now transitioning out of the pride.
It's interesting 'Victoria' was mentioned as a destination for them. Victoria currently only has three facilities with lions; Melbourne, Werribee and Mansfield.
Melbourne can be ruled out, as they don't have the space to accommodate an additional pride. Conversely, Werribee do, with an empty exhibit following Jarrah's death two years ago. I was under the assumption this may be used for Nilo's young cubs when they reach adulthood, but there's a chance Werribee may be wanting to fill up that enclosure sooner rather than later.
Mansfield is potentially a strong candidate; especially with an ageing pair who's enclosure will obviously be soon vacated following their deaths.
I’d assess Mansfield to be the most likely candidate as they’ve traditionally been a non breeding facility. Chad and Ruka aren’t genetically valuable, considering the extensive representation of both their paternal and maternal lines. Placing them in a non-breeding facility makes sense.
With Adelaide’s pair getting on in years, I had assumed that would be their eventual destination; but the deaths of Adelaide’s elderly pair will provide an opportunity to create a new exhibit and it will be a while before they can receive them. Depending on the size of Adelaide’s exhibit, it may be better utilised by three males, which could well be the outcome of Monarto’s latest litter - which will transfer out circa 2025 (when Adelaide’s exhibit will likely be close to completion).
Alternatively, Adelaide may serve as retirement facility for Monarto’s three breeding males. It remains to be seen whether the current breeding females (which will be post reproductive by then) will tolerate new males; but it’s a possibility re. succession.