I think I didn't use the correct phrases to try to portray what I'm thinking. If SOU has renovated, then obviously this isn't required anymore. However, if SOU expanded - if possible, I am no expert in the laws of this - to possibly a bigger runway and increased capacity? Then I wouldn't see why anyone other than Ryanair (would would call it Southampton West) would want to go to BOH unless it was cheaper.
For the time being, it looks like things will stay the same. Other than Ryanair returning for a seasonal run.