To be clear, you can still get points for having a year of Canadian work experience. However you cannot claim the 50 job offer points. That's where the LMIA is needed since you are on an open work permit with no employer named.
There are LMIA exempt work permits where you can claim the 50 points after working for a year for that employer in Canada. However these are closed work permits where the employer is named on the work permit. A good example of this is an ICT (intra company transfer). This is a closed work permit that is LMIA exempt where the employer has transferred the employee from their operations outside of Canada to their operations in Canada. In this example, a person can claim the 50 points for having a job offer after working for a year for that employer in Canada.
But again, in your case this unfortunately doesn't apply - specifically because you are on an open work permit with no employer named. So make sure you are answering "no" to the job offer question in your EE profile.