Stewby,
All very late in the day I suggest,they are masterplans only,no planning permission etc,and even if it was given there is a considerable time for them to be up and running.There is no realistic short term hope of any LCC operations,in the meantime FLybe hang on or if they go it's nothing short of disaster for SOU.
Down the road at BOU things continue to pick,and with a Jet 2 Southern expansion announcement in Jan2019,there is every possibility that Bournemouth is on the verge of really advancing rapidly in the not to distant future!