Another Twist on Neutrality Agreements

Thanks to Workplace Prof Blog for posting this story about a neutrality agreement in the U.S. involving two unions, SEIU and United-Here, and two employers, Sodexo Inc. and Compass Group.  The agreement permits the employers to decide which locations the unions can seek to organize and also imposes a quota on the number of employees who can be organized.  The unions also agree not to strike.  In exchange, the employers will remain neutral and not try to persaude the employees to reject the unions.  An odd twist in this agreement is that the details of deal, including how the permitted sites are selected, must remain secret.  Here in Canada, we saw recently the CAW bargain a neutrality agreement with Magna in which Magna permited CAW organizers onto its property to organize workers and agreed to voluntarily recognize the union if a majority of workers in a factory voted for the union.  In exchange, the CAW agreed not to strike and to include in the collective agreement a variety of administrative and grievance structures that Magna uses in its non-union facilities.
These agreements are clearly designed to bolster union density rates at a time when unions on both sides of the border are facing an organizing crisis.  There are a variety of interesting legal issues related to these sorts of agreements (you can read about some of them in my paper on neutrality agreements).   For example, in Ontario, labour legislation prohibits employers from providing “any support” to a union during an organizing campaign.  If an employer does so, any resulting collective agreement is rendered void.   Why do you think that law exists?
Do you think the employers in the SEIU-United Here agreement provided above would be providing “support” to the unions under Ontario law?  What about Magna, when it invites the CAW organizers into its factories and encourages its employees to support the CAW?  Should the law prevent these sorts of voluntary agreements between unions and employers?