my current situation is i am waiting for PPR...i can extend my work permit with reference to existing AOR and can remain in canada until the decision is made.
If you have an AOR for a CEC application that is in process, and you are in Canada, you can apply for a BOWP. If you get the BOWP, you can remain in Canada until it expires. Of course, if your PR application is approved, then you don't have to worry about an expiring work permit any more.
i have a question like if anyone who have been waiting for PPR and also might have submitted the profile under express entry category then if they get the invitation to proceed further.
Some have, if they are uncertain whether their current application will be approved. But it will not "speed up" the processing of your existing application. If they then get the ITA, they have to make a decision about whether to submit a 2nd application (it is allowed).
will there be an option for the express entry candidates to apply for the BOWP and to remain in canada provided they are already in canada.
No change. There's no BOWP for people who submit an EE profile, but those who get an ITA and submit applications remain eligible for the BOWP under the same rules (e.g. for CEC applicants, if you get the AOR, you may be eligible for a BOWP if you are within 4 months of the expiry of your old work permit...)