routes without grades?

I saw a few routes recently that just show up with a star rating, but no grade (e.g. doesn't show "5.9", "5.10", or whatever).
Here's one: https://www.mountainproject.com/route/109687950/the-big-dipper

Are grades optional when submitting a new route to the site and have I just been lucky so far in seeing only those where one has been provided?

That route is attributed to the Orphaned User account so the account that originally submitted it got deleted. It seems like the originally-submitted grade got deleted, too. I refreshed the page so it now shows the only other user-submitted grade (5.12a) and it should tally future grades and show the consensus i.e. median as normal. 

Thanks Zander. Is there a way for you to detect and refresh those en masse?
Here's another one, probably from the same orphaned user - https://www.mountainproject.com/route/110325415/hurtin-for-a-squirtin

I’ve come across routes that are missing grades/types but still have the submitted account (not Orphaned User). Originally reported this like a year or two ago but didn’t get a response.

Examples: mountainproject.com/route/1… ; mountainproject.com/route/1…;

The route page is set to refresh the consensus grade rating whenever a new grade is submitted. So in these cases, whenever a user submits a new grade rating, the page should update accordingly. (For what it's worth, this is also true if you submit a bogus rating and then delete it after the fact. It sill forces the page to refresh so all I'm doing to "fix" these is submit a grade rating myself by looking at what others have submitted, hard refresh the page, and then deleting my rating.) Please check me on this if you end up testing and getting different results. 

On the Grading topic - If several climbers think is route is mis-graded, is there a way to edit/change it?

When you click "Edit" at the top, the box that opens allows to submit changes to name, Fa, etc, but not the Grade...

Not that I know of. The original contributor (or any other user who submitted a grade previously) could change their "vote," otherwise, the consensus (median) would adjust as more grades were submitted.