You haven’t informed anyone of any such thing. Wikipedia does not generate original concepts on purpose and you are complaining that an equivalent term exists for other presidents. Right now if Wikipedia was to create pages for those terms, _that_ would actually be bias as those terms aren’t widely used/don’t exist and would only be added to meet some people’s concept of “fairness” where if something bad happens to my side something bad has to happen to yours too
Edit: Also as someone else pointed out the page describes the origin of the term as evolving out of Bush Derangement syndrome being coined in 2003 and even comments on a Thatcher Derangement Syndrome phrase used after her death. The Trump Derangement Syndrome appears to be the main article because of the actual usage by government and in legislation