Congratulations to Norway - winner of Bermuda Bowl, and to the US as winner of Seniors and I'm just not sure who to congratulate for winning the Venice Cup (the players I guess since they wish to disown affiliation???).
I will not enter into the merits of the sign itself or of the current administration/President of the USA.
No one here has suggested that the sign held up was anything less than poor taste - and as I believe Voltaire is alleged to have said "There is only one great sin: vulgarity".
The action should be condemned for bad taste at the least.
Freedom of speech is NOT a worldwide right: quite the reverse in a multitude of countries. It is an egregious mistake to take for granted and assume that in which you believe is believed/revered or even given credence by others.
Even in those countries which do promulgate "freedom of speech" it is constrained by common law eg sanctions apply for shouting "fire" frivolously in a packed movie theatre...
As in so many cases you may hold any opinion you like but your right to promulgate the opinion is not unfettered.
In this instance the players of the victorious Venice Cup team were present in a representative capacity, and the obligation is to the group they represent.
There is also a wider obligation IMHO: not to politicise bridge or indeed to use a representative capacity for limited purposes to pursue your own hobbyhorse (whatever it may be).
Whether it is accurate or not, the making of "motherhood statements" (and obviously from the comments there are posters who would regard criticism of the current President of the USA as a motherhood statement) is similarly inappropriate, unless they have some fairly direct relationship to bridge/the championship.
I echo the views already expressed by others as to the capacity for what one group calls "obvious truth" to be deeply offensive to another.
As to any sanction to be applied, that will depend upon:-
a) who had prior knowledge of the holding up of the sign;

the existence and terms of any code of conduct/terms signed ;
c) the intestinal fortitude of both the administration and the participants.
Presumably there will be an inquiry (almost an inquest) and were I engaged to provide advice to the participants, I would recommend a pre-emptive apology both to the sponsoring bodies (WBF and Chinese Bridge Federation, and to the ACBL and USBF) for any offence given, the poor taste exhibited and an undertaking to act appropriately in future if provided with the opportunity to represent the USA.
I note that euphoria might be an excuse but what may be excused more easily when done by teenagers (perhaps athletes), is harder to excuse by mature adults who have just won a world championship which as a representative unit - which world championship was based on intelligence and judgement!!
Of course to play devil's advocate, some might argue that given the aforementioned requirements of judgement and intelligence, any need to specify the sign's contents is rendered superfluous (but of course that only furthers the argument of bad taste at the least!).
regards,