the Material is similar but the format of the stems will be very different. Much more similar to reading published data on the new MCAT, rather than simplified “a boat crosses a river at a x° angle” like with the old MCAT.
personally, I would avoid materials intended for the old MCAT. There are lots of free resources like Khan academy. I would use that and then spend any additional $$$ you might have on buying full length practice tests. Good luck!
I used strictly old TBR (2012/2013) for BB and CP and it was more than sufficient. You may need to skip certain sections; stuff was taken out. In fact, I think it was overkill.
For verbal, timing and pace has considerably changed. Also, there aren't natural science passages anymore.
P/S is entirely new and I recommend KA and Anki for it.
It's definitely possible to use old material, but since so much has changed, especially in regards to format and content, I would really recommend using post-2015 material. That way, you won't constantly be questioning if you actually need to know the information you're doing practice on.