Although pledging her allegiance, the long-distance pressure on the recently-engaged couple's relationship could mean fewer appearances, if not none, from Cullen in future ANZ Premiership seasons and potentially the Silver Ferns.
Silver Ferns sharpshooter Maria Folau made herself available for only a limited number of games for the Northern Mystics this year, as she tried to better balance her time in Auckland while based in Sydney with husband and Wallabies star Israel Folau.
But the constant travel still took its toll, with the 128-test veteran now permanently relocated in Australia and set to play a Super Netball season with the Adelaide Thunderbirds.
If Cullen was to eventually sign with an Australian franchise, she would need to seek exemption from Netball New Zealand to remain eligible for future Ferns selection.
So far, only Folau and Silver Ferns captain Laura Langman have been given the nod to do so. Netball New Zealand confirmed Cullen had not yet applied for an exemption.
Last week, Cullen voiced her support for Johnson on Instagram.
"So happy to see you sign with an amazing club that supports you and your dreams! Proud of you always," she wrote.