It is true if the employer is considered H-1B dependent[0]. For employers with >51 employees if 15% or greater of the employees are H-1B workers then they must attempt to hire US workers first[1].
To be clear, this is not the same level as the green card PERM process (which requires jobs be advertised in physical newspapers, etc).
This simply says equally or higher qualified US workers who apply to the same job should be offered the job, but there is no need to seek out US workers.
> employees if 15% or greater of the employees are H-1B workers then they must attempt to hire US workers first
How does this work exactly? Say I am currently unemployed and match the criteria. They post an ad in a paper, I see it and pass the interview. At the negotiation step (because of course total comp is not listed in the ad), I say I will take the job if they pay 2X of what they would have paid to an H-1B if I did not come (again X was never mentioned, it is just the number the company keeps in mind). What next?
To hire an H-1B, the company has to do a Prevailing Wage Determination (PWD), where they ask the Department of Labor what an appropriate wage for this a) job function, b) experience level and c) geographic area is. To go forward with the H-1B, they only have to offer that much for the position.
This simply says equally or higher qualified US workers who apply to the same job should be offered the job, but there is no need to seek out US workers.