As part of US-99873(For internal purpose) for ML10, the setting "initialization/persistrequestor/usepagelevelpassivation" is being removed. Functionally, passivation will behave as though this is true, which indicates that we are using the "new" passivation model.
If the setting has been configured as false, an infoForced message will be output from PRSessionProviderImpl at initialization.
"The setting initialization/persistrequestor/usepagelevelpassivation has been configured as false, but this setting has been deprecated and will be ignored. Page-level passivation will be used."
And to answer your question
Suppose if I am working on 7.2.2, will strictly follow up the same version of help, or even previous version of contents are available too?
Ans :Help Documents are created for each pega release and you can follow for that particular version .