Could York Strikers Return to Work While the Strike Continues

While I’m dealing with the York strike (again), I want to address another question I was asked the other day by a member of the striking CUPE union:  Could a striker ask the employer to return to work while the strike is still continuing?
That question is actually dealt with in the Labour Relations Act, in Section 80.  What that section says, in a nutshell, is that at any time during the first 6 months of a strike, any person in the striking union can inform the employer, in writing, that they wish to return to work.  The employer must then reinstate the employee, on whatever terms the employer and employee agree.  So far, that might suggest a striking CUPE member could tell York she does not want to be on strike anymore, and the employer would then be required to bargain terms of reinstatement.  This sometimes happens when employers continue to operate during a strike.  Employees cross the picket line.  It doesn’t win them any fans among their fellow union members, but it is lawful.  It might violate some rule in the Union’s constitution, perhaps leading to the employee losing their union “membership”, for example.  But the person might care about that, and might not even be a member in the first place.  
But now look at the exceptions in part (2) of section 80.

Exceptions

(2) An employer is not required to reinstate an employee who has made an application to return to work in accordance with subsection (1),

(a) where the employer no longer has persons engaged in performing work of the same or similar nature to work which the employee performed prior to the employee’s cessation of work; or

(b) where there has been a suspension or discontinuance for cause of an employer’s operations, or any part thereof, but, if the employer resumes such operations, the employer shall first reinstate those employees who have made an application under subsection (1).

This language would seem to exclude most of the striking CUPE members, since York has discontinued the work that the strikers perform.  In most cases.  They have, however, reinstated classes in a few places, such as Osgoode Hall Law School, where a number of CUPE members teach.  My understanding is the classes taught by CUPE members at Osgoode did not resume (Is that right?).   But there is probably a decent argument that the the employer has “resumed operations” at Osgoode, don’t you think?    

If so, this would seem to mean that the striking CUPE members who teach at Osgoode, or at any other part of the school where classes have resumed (if there are any such people), could, if they want, “cross the picket line” and return to work.  They would not be covered by a collective agreement, because there isn’t one.  They would need to ‘bargain’ a new contract with Osgoode, but it would be unlawful for Osgoode to propose terms that “discriminate” against the CUPE member.  Usually, this means that the employer offers terms similar to what the old collective agreement required, or maybe what the employer is presently offering the strikers in bargaining.

So, maybe CUPE members who teach at Osgoode, would have an argument that they have a right to return to work (if they so desired).  But I doubt that any other CUPE members do at this time.  Do any of you labour lawyers or students have a different take on this question?