Hi Joe,
I found an article online from 2018 mentioning the Federal Government here had increased the limit from 45,000kg to 50,000kg (Source), however that is really only part of the story. Essendon Fields website reports that any aircraft with Maximum Take-Off Weight (MTOW) of 50,000kg (110,230lbs) or tyre pressure greater than 1400kpa (203psi) requires a pavement concession (Source). From limited searching, it appears the BBJ1 MTOW is 171,000 lb (77,564 kg) and Goodyear reports their tyre needs to be inflated to 214psi. I would imagine the BBJ2 figures would be higher meaning the BBJ requires a pavement concession to land at YMEN.
YMEN website states:
Short Answer: It's up to the Aerodrome Operator to decide whether they accept a BBJ or not. To my knowledge, BBJ's and larger tend to land at Tullamarine instead. 707's have landed there and apparently the maximum to date for weight is 148,325kg - Lyndon B. Johnson's Air Force One C-137 Stratoliner in 1966 and again in 1967. Do BBJ's land there regularly? Not to my knowledge. Could a BBJ feasibly land there? Likely possible with restrictions and a pavement concession.
The Background
Cheers,