Ellieb wrote:But the bike will still be coming up behind them, just on the other side of the path.
Quite - on the other side.
I doubt that the ensuing lateral separation would be enough
Then that route is probably too narrow for the purpose, unless traffic levels are very low.
It is a lot more unpleasant to have a bike coming straight towards you
Not at all. I frequently encounter such as a pedestrian. It is perfectly normal. They either move over to pass, or if oncoming traffic prevents then they slow down until they can move over and pass. Same applies when it is a general-purpose road and it is a car, etc, coming towards me.
If high traffic levels mean that vehicles are frequently having to slow down significantly before they can pass pedestrians, then the traffic levels are too high for the route to be a shared use road or path, and it needs a footway added.
as the OP points out he was concerned that the pedestrian was going to move across as they closed head on & into the path of the other bike.
Which illustrates the importance of everyone following the rules, so their movements are predictable.
It can also be dangerous as pedestrians seem to be less likely to be noticed in poor visibility when seen from behind. That was why the rule about pedestrians walking facing vehicular traffic developed.
The chances of this happening on a cycle path are small
My own experience - of pedestrians in dark clothes emerging out of the gloom - disagrees. In particular, faces are much more distinctive than the backs of hoods.
Out of interest, just how much riding on busy shared use cycle paths do you do?
"busy shared use cycle paths" should not exist - the design is only suitable for low traffic levels.
I do more walking than riding on them. If I expect such a route will be busy I generally go another way when cycling, unless there is no alternative which is not a long way round. Riding on busy 'shared use paths' is generally more stressful and more hazardous than keeping to general-purpose roads. I use lightly-used 'shared paths' where they are useful shortcuts.