I agree, definitely. But here we are, the reality is that people read first paragraphs at best (which there can be valid reasons for) and take away "ah yes, Hawking radiation is a thing black holes do, science says so". A reader who is interested further and has the mental capacities after working 8 hours 5 days a week to scroll down and read about experimental observations might also realise "oh wait, it isn't actually clear whether it does exist" but you can't expect that from everybody (unfortunate as that may be).

This particular instance may be harmless because it probably doesn't affect anything in everyday life. But in general I think a first paragraph in an encyclopaedic source that wants to inform the general public should be very clear about it when a thing is hypothesised and hasn't been shown to exist.