Batman even brings Alfred (Ralph Fiennes) from The LEGO Batman Movie into The LEGO Movie 2, despite Alfred not appearing in the first LEGO Movie.
Without spoiling anything, The LEGO Movie 2: The Second Part does acknowledge The LEGO Batman Movie, at least during the first 20 minutes of the sequel.
In order to keep itself distant from the box office bomb that Ninjago ended up being, The LEGO Movie 2: The Second Part makes absolutely no references or connections to The LEGO Ninjago Movie.
The first LEGO Movie spin-off released in 2017 was The LEGO Batman Movie, which followed the personal life of Batman (Will Arnett) in Gotham.