The network stance on this is that it's fluff and distracts from the main content of the post: Should 'Hi', 'thanks', taglines, and salutations be removed from posts? But some sites deviate a bit from this policy; for example, I've been asked not to remove 'Thanks' from posts on MathOverflow.
Suggested edits which only remove sentences like these are frowned upon by many users, especially if 1) it's an old post and/or 2) there's much more room for improvement to the post. I don't think there is consensus about this, but you might want to take a look at What's the right policy on suggested edit pending on removing user sign or cheers on Meta Stack Exchange.
(Disclaimer: while I do have some reputation on this site, I'm not really a regular. Arqade's local policies may deviate a bit from the network standards and I'm happy to be educated.)