To give a broad answer, I think it depends on where you plan on releasing your film. Some distributors may have minimum requirements. I know that Netflix Originals even specifies which cameras can be used and which settings on those cameras.
But if you are releasing independently on YouTube or Vimeo, I think audiences will be fine with a change in look. That’s what I did with my documentary. I started in 2010 when I didn’t know what I was doing. I started it with a Panasonic HS700. Then years later I shot some of it on a Panasonic GH4. I also used very low quality Skype videos of interviews I did with people online. The people I made the film for don’t care, they care about the inspiring stories, which was my goal.
-Reid