From what I've read, virtually no companies ever relist after having their registration revoked. It's expensive and the SEC looks very carefully at the company.
I would think shareholders would have a course of action, however it's hard to see anyone blindsided when the company doesn't file required reports for a long time.
In HJOE's case they used social media to reassure investors, which may give them additional liability. WSTI seems to be completely silent, which would probably make it harder for shareholders to win a suit.
TA - Over $500 million in toxic funded pump and dumps exposed and growing every day!