Yes, we should make sure that names, function names and acronyms are correctly spelled and applied.
We are used as a reference by students of cryptography. Not all students will be aware of how the terms should be written, and will likely copy the spelling as (mis-)applied on the site. Therefore making sure that the spelling is correct is an important job and warrants an edit. This is doubly true if the misspelling is in the title of the question.
Besides that, correct spelling of these kind of terms are vitally important for having our site look as professional as possible. Professional looking questions and answers are more likely to be taken seriously.
So please make sure that Elgamal*1, Vigenère, AES-128, SHA-256 and SHA3-256 are used correctly.
If there are any doubts on how to spell these names then please lookup the standard in which they are found. When it comes to names, please use the way how an author spells their name themselves in English-oriented material. Otherwise please use the most accepted spelling. A correct spelling can often be quickly found on Wikipedia, we can always adjust when the Wikipedia spelling is clearly incorrect.
Some leniency can be applied if the incorrect term is in common use and doesn't cause any confusion. E.g. 3DES, Triple DES are probably better terms than (T)DEA, the official name for the Data Encryption Algorithm that nobody seems to use anymore.
However, edits that add a single dash on a single misuse - when the term is used multiple times - will still be considered a minor change and may be rejected for that reason. If you're adamant that it is still required, then you'll have to include a good reason in the comments for the system to let such a change through.
*1 Elgamal is how the LinkedIn page and Wikipedia page both capitalize the name. ElGamal should also be allowed due to historical significance but Elgamal should be preferred.