The last news I read on this, the Librem 5 was slated to launch in April of 2019. Is this still the case? Is it usual for an ambitious project like this to be doing this sort of development (i.e. core dev, not polish) within 6 months of release?

I'm really looking forward to this phone and will almost certainly move over if there is are decent mail, Whatsapp and Signal clients. Despite the cost and early adopter pains I'm likely to face :)