They haven't specified if it is only for CELPIP. It broadly mentions "Language proficiency organization" which includes IELTS.we do not know if the screenshot is acceptable for new pathways. The instruction shows that the online portal result could be accepted since as of I understand that the CELPIP result report needs to be downloaded by ourselves in the online portal, and it is a complete PDF format including all the applicant's details in the account. Basically, test takers of CELPIP do not have a hard copy as they need to pay an extra fee in order to receive it.
For IELTS, online results do not include the more accurate info. including the photo, date of result, and officer signature. So, the screenshot is not a complete report, we do not know if this format could be available for this pathway.
In such a case, I guess that the instructions showing the acceptable online portal result mean the CELPIP results. BUT, let us see what is the next step for the screenshot
Moreover, IELTS results are verifiable online so it doesn't require a signature, the applicant's photo as IRCC always verifies it with the TRF number which is included in the online portal results. (Source: EE portals)
My TRF copy took more than a month to arrive due to Covid-19 but I was eligible, so not having a hard copy of the results shouldn't be a disqualification or concern of in-eligibility. the officer can always ask for a scanned copy rather than refusing it on the basis of "Language proficiency" results not provided. Here the question is. whether the online results are true which can be verified easily.
Considering this, giving the benefit of the doubt in this situation to only CELPIP results does not make sense.