Hey!
I checked their Twitter, and they replied to someone with the same question as you;
"Hello! Thanks very much for reaching out, we’re very grateful! Our game is definitely still in development, but we can’t give a firm release date for the next two routes yet. Hope this helps!"
So, in short, yes! It's still in development! It'll just take a while for the next update to be released.
This response from them was posted on March 21st, so I imagine the next update will release soon, though that's just my speculation.
Hope this helped anyone looking for the same answer!