Standard practice was to remove the URL because it created a hyperlink from the webpage that would compete with the one created by the Wikitree template.
I know this was a hot topic a few months back, but the format provided by Find A Grave in the past was correct as copy/pasted (with the extra findagrave website link). I know many members removed this extra link, but it was not needed, especially when the template was added to the citation. So the guidelines on using the template will not change, but will be modified slightly to accommodate the new citation format.
When given the following citation:
Find a Grave, database and images (www.findagrave.com/memorial/110540273/henry-h.-harris : accessed 26 April 2021), memorial page for Henry H. Harris (27 Aug 1856–28 Aug 1922), Find a Grave Memorial ID 110540273, citing Tubbs Cemetery, Kings Mill, Walker County, Alabama, USA ; Maintained by Diona Dickerson (contributor 46857758) .
You can modify this to following:
Find a Grave, database and images (www.findagrave.com/memorial/110540273/henry-h.-harris : accessed 26 April 2021), memorial page for Henry H. Harris (27 Aug 1856–28 Aug 1922), {{FindAGrave|110540273}}, citing Tubbs Cemetery, Kings Mill, Walker County, Alabama, USA ; Maintained by Diona Dickerson (contributor 46857758) .
(Note: the bold is where the citation was modified to include the WikiTree template).