Hello. In order for PDF with scanned pages to be PDF/A compliant, the scans must be run through OCR and then the file saved as PDF/A. If it was able to be saved to conform, then the properties can be checked to verify. However, note that because OCR is REQUIRED, the resulting text may have a lot of mistakes; it depends on how good the quality of the original scan was.
I suggest you send me 5-10 PDFs to convert to PDF/A and I will let you see howthem come out.