When we are writing a thesis, we always have rules and guidelines that are needed to consider as always. These set of rules and guidelines are standards to have a smooth flow of smoothness. Your adviser or your thesis consultant will explain it more to you. These sets of requirements are also set by your university or sometimes by your course department.
It always depends but we also have universal guidelines. Some universities adopt this system but some will still consider their own guidelines. These guidelines will set formality and uniform thesis. This is to organize more all the millions of thesis in the world and have a proper documentation of all of them.
One guideline will talk about the thesis word count. This word count needs to follow. If you are asking if there are some cases that someone will exceed to the number of word count, yes there are some. Those who exceed the given number will need to defend their reason why they do not comply with the set rules. They need to justify that they need more to elaborate more their study. Get detailed info about how long is a phd thesis on this site.
The number of words will also take consideration of the spacing, margin, font styles, and font size. There is also a need to be uniform in this matter. Critics will be sensitive on this matter. If you are going to think that these critics will check hundreds to thousands of theses they will definitely demand an organized one for them to read well and understand well the content of the whole paper.
No one will want a thesis that looks like a draft after the said deadline. Yes, a certain thesis will undergo several drafts after several rechecking but if it is already a final or finished paper to be published, proper requirements should and must be followed.