Don't be obtuse. I was asking about specific FTL which you dubbed as Reaper FTL implying it is faster?
Which is already their mission, so why tell them again? Especially considering the fact that it will take hundreds of years to reach them. Who would volunteer for the telegram mission? To abandon their lives behind without the threat of Reapers that the original expedition faced?
Again, it will take YEARS (decades really) to apply it in any viable capacity.
What NEW expedition? Why do they need NEW expedition? Why would they send it using 30x times faster FTL (if it exists) do you realize they will arrive faster and will have to wait HUNDREDS of years for the original expedition? Some mission - fly to Andromeda and die before the first expedition arrives. Or what waste the time in stasis, why the faster FTL then? And who would volunteer for such an insane mission?
No it didn't, as Hackett put it - it was quite simple in design technologically simple and very easy to built hence why they even started building it.
What theories and discoveries?
What entire galaxy? Entire Milky Way galaxy haven't even been explored yet, because races were contained in the Mass Relay Transit net.
And there's a clear limit to the manpower that can do the job. Not every sentient being have the qualifications. Hence the logistics. Repair Mass relays or build new ships for new expedition which is clearly NOT needed at all.
If I was in charge back in Milky Way I wouldn't send a second expedition to Andromeda at all even if I had resources. Even if I knew about it to begin with.