If your water provider says it's potable I'm not going to question it, but I have yet to see a provider that makes such a claim about their hot water. It is difficult to make a statement that would apply worldwide, but where I live, it is easier to keep legionella out of cold water even if the infrastructure for hot and cold is the same.[1]
We are supplied cold water which then goes through a hot water system. My understanding was that the new configuration required the use of check-valves to prevent backflow in such a way as to reduce the risk of cross-contamination between hot/cold. I'm guessing this is now irrelevant because hot water system standards have changed to reduce risk of corrosion / infections occurring, but there is also a chance I was getting mixed up with UK regulations [0].
[1]: [Czech language] https://www.moni.cz/aktuality/tepla-voda-jako-pitna