At Detailed conformance information we suggest to display:

Reason why the publication does not claim to meet the standards. For some jurisdictions, it may be important to indicate why a publication is not compliant with the standards, such as if the company is too small and therefore not required to, or if the cost to produce the accessible version is too high. Showing this information may be important if required by local legislation, otherwise it can be omitted.

That's materialised by EXAMPLE 7:

Unknown accessibility conformance statement with detailed conformance Information
Conformance to accepted standards for accessibility of this publication cannot be determined.

Detailed Conformance Information:

The creator of the publication is not required to publish in an accessible format because it is a micro-enterprise (e.g., enterprises employing fewer than 10 people and with annual turnover or balance sheet total not exceeding €2 million).

While this information is of use for control authorities,

1. is this information valuable for the end user? and
2. do publishers want their ebooks to be displayed with negative statements while in fact they will still probably have most of the accessibility features?

A side effect to consider is that an ebook can be made fully accessible because it's only text with a cover and logo as images, but to avoid burden and cost, the publisher indicates being exempted for micro-enterprise. Some people may interpret this ebook as not accessible enough for them, while it is not the case.