This is last alpha. Next release in pipeline will be first Beta.
Also I would cut BS folk some slack. They are maintaining most popular OS project on Github. The maintenance burden for previous release was unimaginable and terrific, effectively pulling them down until they decided to make harsh decision of ceasing work at Bootstrap 3 and focusing at BS4 exclusively.
It's also worth noting that the lead maintainer, Mark Otto, is also simultaneously heading design at GitHub as well. Not entirely two small things to deal with in your life, ha. :)
Also I would cut BS folk some slack. They are maintaining most popular OS project on Github. The maintenance burden for previous release was unimaginable and terrific, effectively pulling them down until they decided to make harsh decision of ceasing work at Bootstrap 3 and focusing at BS4 exclusively.