Oh man, I am SO hyped for the Goonies stuff. One of my all-time favourite movies and it'd translate to LEGO gameplay so well
The offline aspects are still plenty of fun - playsets provide story modes that last at least 5 hours each, a lot more if you go after 100% completion. You'll also be able to build your own levels and sandboxes to play around in still, you just won't be able to download anyone else's.
You can also reroll and add slots by using coins, but I think you need to have hit Level 20 in order to do that from what I remember.
The post-launch support has been great, they just kept adding new maps and weapons in for free beyond what was locked out on disc, while they could have easily charged for a season pass.
On the plus side, you'll probably be able to play through the Story Pack with Venkman instead if you wanted to. I doubt the new Ghostbusters will have different abilities. I'm not sold on the reboot yet but the ghostbusting in the base game was fun so more of that should be good.
I'd put money on them waiting for a Smash Bros. enhanced port for Switch. They'll release them the same day and capitalise on the hype