Offset feed rectangular waveguide

I am confuse with the design of this commercial product (product no - AN-3456-10), this is a Ku-band LNB .
it has rectangular waveguide for connecting antenna and that waveguide is connected to active component. transition from rectangular waveguide to microstrip line is through a probe which is not center feed.
the center feed is most common design I found so I was confuse why this design has feed position not at center.

The data sheet for A-3456-10 is not available, even the company selling it has not able to provide data sheet for this product.
I waveguide pic and active circuit pic is attached.

Kindly give your suggestions.

Thanks

To enable maximum coupling of fields to the probe, should carefully design the appropriate height and position of the probe.
The distance from the probe to the lateral walls should be λ/4:
../imgqa/eboard/Antenna/rf-pjwwknoxfjl.gif

Thanks vfone
as per maximum coupling is concern I feel the probe should be at center. bcoz for TE01 mode the fields are maximum at center region.
that λ/4 criteria also in a way suggest to keep the probe at center from side walls.
Thats why I am confuse why this commercial product probe is not at center. ... searching little bit I found many such commercial products have off-center probe.
I really wonder why ?

I found that the offset of the probe is done when the LNB is used only for horizontal polarization, or for horizontal mounting on the antenna and use a polarization changer in front of it.

Also I found that some microstrip probes inside of the LNB are not in perfect vertical position, as in the example below:
https://imgur.com/0reBZGP

Some of them have an offset of few degrees (3.5° to 7°), which is used to reduce cross-polarization interferes when receiving signals from some satellites:
https://imgur.com/mccYZv5
https://imgur.com/MHXiiTP

this fact sound very interesting. can you give any reference to learn more about it.
Thanks