DUP Communities Minister Gordon Lyons has already been granted permission to intervene proceedings based on his opinion that the decision was cross-cutting.
With the challenge originally set for a hearing later this month, Irish language rights group Conradh na Gaeilge and TUV MLA Timothy Gaston lodged further applications for participation status.
The imminent appointments of Northern Ireland’s first Irish language and Ulster-Scots commissioners were also raised.
Mr Justice McAlinden indicated the commissioners should also be consulted in a bid to defuse the argument.
Conradh na Gaeilge welcomed moves to seek the opinion of the Irish Language Commissioner, describing it as a “sensible and prudent” step.
The group’s President Ciarán Mac Giolla Bhéin, said: “We would anticipate that the commissioner will come to the conclusion that dual-language signage in shared spaces is a best practice model enjoyed and enshrined in other countries with similar circumstances, ultimately supporting the minister’s original position.”
TUV MP Jim Allister said he “welcomes” Mr Justice McAlinden’s comments.
“The core legal contention always was that this controversial and divisive decision required executive agreement,” Allister said.
“Now, after the Sinn Féin infrastructure minister has squandered public money pursuing her own agenda, she has been told she must do just that.”
He added: “It is now for the DUP to make clear at the executive table that they will not allow the imposition of Irish language signage at Grand Central, and that no such agreement is possible.”
BBC News NI have contacted the executive for a response.