I have a lot of family that has the same cultivar of rhubarb, but it never seems to flower (from the same mother plant that we split the roots apart over 30+ years). Why do people say that it flowers, when it never has for us?
Well it can and does flower under certain conditions; first, some varieties are more prone to bolting or flowering, but otherwise, the factors are usually maturity, or conditions such as a very warm spring might trigger flowering, or stress such as suffering drought. Rhubarb crowns which are lifted and split when they get large enough are less likely to flower than crowns left alone to get very mature. https://www.gardeningknowhow.com/edible/vegetables/rhubarb/rhubarb-bolting.htm