Should I Internal Link My Entire Site?

I bought a big site a year ago and it was a mess - 10k posts, but was dead from a ux and ads perspective. I have turned the UX and content around and we are now the largest site traffic wise in our niche - 2.5m visitors per year, 5m page views. HOWEVER - the internal linking on the site is terrible. 8,000+ orhpaned pages. I have recently been trying all the AI internal links too - short version - mostly terrible, Kaola AI is REALLLLLY good. I will put a post up about my experience with all the platforms soon, but basically I can trust Kaola to put relevant links in across the site. SO - advice please :) Should I pull the trigger and internal link across all 12k of our pages? The internal links are all good from Kaola - but will doing it en mass casue issues for seo? Has anyone done this before?