The rules say no such thing, and seem pretty clear to me.
4.10.1. The dress code is strictly observed for the
tournament and all the official events and press
conferences.
4.10.1.1. Dress code for men.
Shoes: Oxfords, loafers, leather shoes or boots, classic
suite shoes.
Dark-coloured pants: black, navy, grey, beige, brown, in
any case unicoloured. No bright colours.
Long-sleeved light-coloured (white, light blue, beige,
brown, etc.), blue or black shirt, in any case
unicoloured. No bright colours.
Dark-coloured jacket, waistcoat or cardigan with
buttons: black, navy, grey, beige, brown, in any case
unicoloured. No bright colours.
Jacket, waistcoat or cardigan may be taken off during
play.
Tie is not mandatory.
[...]
4.10.1.3. No players with t-shirts, jeans, shorts,
sneakers, baseball caps or inappropriate dress are allowed
in the playing area. Any requests to wear national or
traditional dress shall be approved by FIDE Supervisor.
[...]
4.10.9. If a player fails to fulfil his/her duties listed
in Articles 4.10.1, 4.10.4 – 4.10.8, he/she can be
penalised by FIDE Council as follows: 5% of his/her prize
money shall be forfeited to the Organiser and a further 5%
to FIDE for each breach. In cases of serious misconduct,
the player may be disqualified from the event.
Reference:
https://www.fide.com/docs/regulations/wrbc_regulations_2024_...