How do I know? Years and years (and years!) of research, collecting, and spending far too much money. As Michelle says it`s not a hobby. It`s an obsession. And I can`t deny it.
Regarding Italy, info on future phases is really hard to come by. I`ve pieced together what I know from official sources and little talks I`ve had over the years. As I can figure out the ride was always a phase 2B proposal. Phase 2A was to have been the roman ruins wallaround, leading eventually to the gondola ride (the boats were never bought - the ones docked at the Isola were built for that purpose). The west side restaurant was planned in late 1983, but for reasons listed below - money and timing - was never built either.
In 1980 Rhine River was to be built, with Meet the World. El Rio Del Tiempo was to be a phase 2 attraction. MTW had design issues, and Rhine River was mothballed with just the queue and load building complete due to the over budget and over schedule of the park. They simply didn`t have enough time or manpower to open by October 1st - taking the RR crew off and not addressing the problems with MTW would help the manpower situation, but not the budget. There was no chance Italys Gondola ride could be built too.
With no MTW, Gondolas, RR or EL Rio, plus Denmarks water ride being scrapped with the pavilion World Showcase capacity was well below the planned level. Soloution? Build El Rio and add the others as and when. El Rio was the most advanced down the line ride, with the lagoon area planned and ready to go, plus half the ride area and load/unload areas also planned for phase one.
EPCOT Center opened twice over budget but on time - and with an extra $100m planned to be spent in its first year with commited sponsors any chance of seeing the phase 2 attractions mentioned above built was remote since all eyes were on Horizons, JIIs ride, Morocco and The Seas.
By the end of `83 Morocco was underway, JII and Horizons were open, The Seas was back on the draqing board (and almost `Living`) but the company was in a finnancial mess due to EPCOTs over run and TDLs manpower demands from WED. And of cousre in `84 management changed and the rest is history.