More highway Blossoms is on the way in a bonus DLC set after the end of the main story. This is not HB2. More like HB Iceborne.
Plot Summary from this page HERE:
After three long years, Studio Coattails, alongside our friends at Studio Élan, are proud to present Highway Blossoms – Next Exit, an all new DLC that continues the story of the hit visual novel, Highway Blossoms!
Set one month after the original Highway Blossoms, Next Exit once again follows Amber and Marina as they return to glitz and grit of Las Vegas after being invited to an alien convention by an unusually depressed Tess. But this time they aren’t gambling with gold, they’re gambling with their relationship…
Highway Blossoms – Next Exit will feature the return of the original voice cast. As well as the return of Syon Santeria (National Park Girls) and Josh Kaplan (Heart of the Woods), who penned the original script. CG art is being handled by Moekki (Katawa Shoujo), with assistance from KamiFish (Katawa Shoujo).
The main six voice actors and writers will all return. The DLC is scheduled for an Early 2020 release.
PS: This will be an “all-ages” DLC.