In general the "command syntax" fails when referencing to function handle that stores in variable
>> mystrcat = @strcat
>> mystrcat a b Error: "mystrcat" was previously used as a variable, conflicting with its use here as the name of a function or command. See "How MATLAB Recognizes Command Syntax" in the MATLAB documentation for details.
% I actually can't see any detail on this specific case in the doc