Hi,

if you look at the change history (1) of this way, you will see that I am the one who marked it as private, in version 2, a few years ago. I did it because the track was barred by a chain and there was a sign stating that this was a private property.
In version 3 another mapper deleted it. The change comment was 'weg afgesloten'.
I've seen that path barred by a chain a few times but it is not always the case.

You might be interested to know that the Flemish administration does maintain a register of public ways (2). It is also available as a layer on iD editor; look for 'Digitaal Vlaanderen Wegenregister'.
If you look at it you will see that other paths on these fields displayed but not this one. This makes me think that this one is on private land.

My assumption is that the owner do place the chain when work on the field is needed and leaves it open the rest of the time so the acces tag value should be, at very least, permissive


1) https://www.openstreetmap.org/way/869100424/history
2) https://www.vlaanderen.be/digitaal-vlaanderen/onze-diensten-en-platformen/wegenregister