I wouldn't either necessarily, particularly with a bypass that can be more prone to dumping, but some plans do permit it, usually in dilute form. I had a juice box in the hospital (but our diet was somewhat more "advanced" than most, being on soft and puree foods as well at that time.)
There are many foods that may not be the greatest thing for weight loss intermediate to longer term that can be useful in small amounts in the shorter term transitional period - mashed potatoes are another common soft food item that has value at this time that we may rather stay away from later on (or maybe not - lots of potassium in there...)
It's a big YMMV thing, and there is no definitive right or wrong answer, and sometimes specific problems, such as the OP's can have solutions that seem counterintuitive to some.