Is it OK to change my research tools/methods completely after/at the end of my PhD? In my Phd, I was using tools of stochastic geometry for my research. But I realize now that the juice has mostly been drawn of this tool at this stage and the new kid around the block is now Game theory, Machine learning (ML), and AI in my field.

I don't have any idea of ML at this stage, but while I am writing my thesis, I am now taking an online course for it. I just want to ask if it is OK to change my tools of research after I have done my PhD with another tool, and if I apply for a post-doc position, how will my recruiters judge me.
Undoubtedly, to me, the answer is yes. I am free to learn whatever I want, whenever I want, and do the research I want, as long as it is following right scientific methods. I may even think of multidisciplinary research where I can learn other disciplines and integrate them in my research. Science is all about curiosity and continuous learning and exploring.