When did the Arks leave exactly?

It should be mentioned that to receive those messages, they definitely needed QECs (since they were traveling at FTL). So apparently, they brought at least one QUEC to link them to the milky Way (which would make sense). So to receive these messages, they could have been as far away as they wanted from the MW already. I guess after they received it, the QEC broke either on their end or on the MW end (which makes sense within 600 years I guess), so they don't have contact when they arrive in Andromeda.

Oh I don't doubt they could introduce some new face. Thing is though that the entire set up for "The Benefactor" sounds EXACTLY like a TIM plot line. It would be just like Bioware to pull him out of their back pocket, be it as a throwback or as a legit story telling mechanic. It would NOT be like bioware to introduce some NEW person that fits the exact same puppet master with money, baut-and-switch shennanigans.

Another rich eccentric anonymous bankrolling power player who is not opposed to espionage/murder to see his vision fulfilled? Mehhhhhh.

The only way it would make sense to introduce a new character in that vein would be to have them in cryo on the arc waiting to wake up and continue their shennanigans.

I'm fairly certain we're going to see TIM as the benefactor with some Envoy on the Hyperion continuing his will.

Hell it'd be more like bioware to have some clone of TIM on the ship than to replace him.

Look for martin sheen's name tied to Bioware sometime in the future.

We will find out in the DLC !

yeah exactly my guess would have been the Milky Way end though given the reapers were attacking and they were finding it hard just to talk to each other let alone the arks that just left. Remember there were issues with Shepard at times trying to get communications out in ME3 at the beginning of the game and again later on as well when they tried to talk with Hackett or Anderson.

Yes BUT, imagine if you were the Illusive man:

That assumes that you can just repair a broken QRC on one side. I guess it's likely that once the pair of entangled quanta is separated, you cannot just re-establish it at range. At least that's my head canon. The only alternative I can see is that the reapers won, which would make the ME3 EC's refuse ending canon.

put away your tin foil hat on that. That would require way too much info then the people in the milky way had about helios. None of that could of been planned.

I always assumed it was after the SM but before Arrival. Has bioware even canonized when the the bridging DLCs for ME 2 takes place?

I always do LoTSB and Arrival after the SM.  There is a reason why bioware made two different holograms for Harbinger.  So I guess when it comes to the arks leaving bioware can only tell us if it was before or after the SM.   They don't want to canonize the rest of the ME 2 to ME 3 timeline.

Realistically speaking, the Arks probably would never made it out of the Milky galaxy, they would be boarded and impounded by the Systems Alliance for the presence of illegal AI technology when passing through controlled space.

Then again Salarian females were supposed to be extremely rare according to the codex and in Andromeda they're suddenly everywere.

Who or what is TIM?

I have not encountered this being anywhere in the games