Hi. Immediately after surgery I was told coffee is too acidic for your new pouch. Which in the early days is still an open wound. Also, caffeine is a diuretic. When you are struggling to get enough fluids anyway, you can't really afford to be losing them at an even faster rate. I did not give up coffee forever, nor was I told I would have to.
As Diane stated, do what your bariatric medical team tells you. Just because someone else did not have to do a liquid diet or drank coffee the day after surgery does not mean you can or should. You should follow the rules you were given 100%. The very beginning is not the time to start playing fast and loose with the rules.