When I check my past questions I see words wahabi are deleted or edited to Sunni?
What is the reason for this action without any kind of notification for asker of question?
The term wahabi and sunni are different . So replacing every wahabi with 'sunni' is not a good idea .But in most of such the questions wahabi is referring to 'sunni. So editing is not bad. but it is not a General rule
Such edits should not be made. Because it's against the spirit of editing. If OP is using term X to refer to a sect or a phenomenon that is relevant to the question then let it be the way it is. Specially when the term is Islamic or has to do with a system of belief.
What you (the editor) thinks are equal isn't necessary equal according to the system of believe the OP has or is trying to reflect/highlight in the question.
The spirit of edit should be:
Make your edit count for the better not to reflect your believe and opinion!
OP is usually (sometime they don't. Don't know why.) notified of any edits that are made to their posts and if they feel that edit is not what they meant then rollback. Or if there are other changes that were in accordance to the above guideline then edit the part that you don't agree with and save. Tada. How easy that was? :)
Caveat: Make sure you provide a good edit summary in such case for future editor of the same ilk.
And if the one who edited it sees that their changes were removed. Or the someone else who wants to make a similar edit and sees that OP doesn't find it right. Then leave it. Don't get into an edit war