Hi Diki
Couldn’t find anything about chord recognition directly, but in the style edit section it does mention about changing chords.
The following info is taken from the Wersi OAS 6 programming manual, and as far as I am aware is the same with OAS 7, however the OAA software may be completely different in the way it achieves the results. (It has very little in common with the standard style system)
Hope this is what you are looking for.

Bill

The setting is called Pad Mode, and all tracks are treated independently.

With the choice field Pad Mode you determine how the style player will treat playing notes if a new chord is performed on the lower manual. This affects the tracks ACC 1 to ACC 5.
Depending on the instruments in use and the reference notes in the accompaniment track, it may be necessary to finish overlapping chords with a chord release. Especially with space sounds, resp. sounds with a long sustain, such overlapping might result in ugly dissonances. You can prevent this from happening by setting the right pad mode. Touch the choice field and select the desired pad mode by turning the Data Wheel on your control panel. The value off means, no overlapping treatment is applied. Set the value to Off, if your track contains percussive sounds, or if the track contains many short notes. Cancel allows the notes to play to the end only if it will not violate the harmonics. This is the correct mode, if your track contains half-percussive sounds with many different chords, e.g. an E-Piano. The setting Trigger will stop all playing notes which do not correspond to the new chords and trigger them again in the right position. Use this mode for pure space sounds, with only a few chords, lasting the whole bar (e.g. strings). The setting Pad Mode has no effect for the tracks DRMI, DRM2 and Bass.