Why does this use An bhfuil instead of An mbeidh?
Because of bí it seems. From GnaG:
> A use of the present tense in place of the future (as in German) is not common, except sometimes by the verb bí.
Go luathmeans early though???
It can also mean soon.
‘Ag teacht’ is both present progressive and near future?
I think it's for any sort of progressive verb.
i guess ag teacht means coming?
yes. I came across " teacht" in the intro to this video and in the chorus of the song "anois ar theacht an..." https://youtu.be/bzXswoAUi0U
I think that here, teacht is the verbal noun of the irregular verb tar, to come