Since we've had only the opinion of a few individuals, I'll add mine.
IMHO, disclosing salary range doesn't equate quality of job offer. They are just unrelated, and as @cedric said, you can cheat on the offer post anyway.
Now, I think another channel, with the current rules of this one, should be created, under a name like #jobs-with-salary-range or #hiring-with-salary-range and this channel should drop the salary range requirement, but enforce quality on other criterions, which should be discussed. At last, a Slack channel is not a recruitment agency anyway.