If it's a toilet marked with the stick figure wheelchair symbol - the international symbol of accessibility - whoever's dealing with this needs to be aware of the legalities.
That symbol's meaning under ISO Standard 7001, which deals with public information signs, is this (with my paraphrasing as I don't have my copy of the standard to hand):
With two exceptions, the symbol indicates that the designated area is mainly, but may not be wholly, accessible to someone in a wheelchair.
The two exceptions are when the symbol designates a toilet facility or a lift (elevator). In both those two cases the designated area, including all its services and facilities, are accessible to someone in a wheelchair.
And that's all that symbol says. It does not mean that the area designated is reserved for wheelchair users, or disabled people only. The facility is always unisex. The symbol is the colour it is because ISO 7001 symbols always are - think motorway signs - these are covered by the same standard.
As that symbol confirms that the designated space is unisex I personally think stating that it's a gender neutral area is unnecessary, and could lead to confusion and some arguments. It suggests to me that the person/people proposing this, don't actually know what that symbol means or the international agreements that govern it.
Also, it isn't a 'disabled toilet', it's an 'accessible toilet'. The need for accessibility is personal to the user and not for criticism by anyone else. Accessbility for one user might be the need for a space for a child in a buggy and nappy changing facilities; for another it could be help for a wheelchair user to transfer from a wheelchair to the toilet; for another it could because those toilets have, or should have, disposal bins suitable for incontinence pads and pants; for someone else it could be to be able to deal with a colostomy bag and to clean themselves as necessary.
The need is personal to the user and asking someone to justify their use of it is unacceptable, and in some cicumstances can be illegal, leading to a claim for discrimination and/or damages.
If this toilet does have that blue and white stick wheelchair symbol on it, don't remove it, but the management should get a copy of the standard and make copies of the relevant section available to anyone who queries it.
In my past employment I've had formal responsibility for ensuring that staff knew what the symbol meant and who was allowed to use the accessible toilets - everyone is.