Though the episode is titled "Thanksgiving", it doesn't lean into the theme in ways that other holiday episodes have in the past. That being said, it does end with something significant to be thankful for.
It's episodes like this one - installments that draw on how well we know these characters and how well they know each other - that makes sticking with a show past its prime worth it.
As for Diggle's role as the Green Arrow, Oliver still says the job is his once he gets well, but it's unclear if he ever will. This felt strange for me, it felt like that storyline was coming to a close and now the show insists on keeping it alive.