Barenreiter do say all the ornaments are probably spurious so I wouldn't sweat over them.
In fact the autograph from JSB is very incomplete, large parts of suites 1-3 are missing and suite 6 is missing entirely. And even for those that are present, only some mouvements seem to be in a fair copy state. Many mouvements are obviously in an incorrected state that shows that Bach was still working on them. Therefore all urtext modern editions consider and use several sources of which primarily copies of pupils which are considered to include revisions made by Bach at a later stage. There is no autograph copy for suite 6, therefore there are 2 main sources, the Altnikol copy and the Vogler copy (with additions from some other copies like Gerber).
They are all extremely close to each other which does seem to support the idea that they are taken from Bach. The NBA has published the 2 versions, the one from Altnikol has much less ornaments. Most editions use the Vogler copy including Barenreiter, Henle, ABRSM. The Vogler copy seems quite reliable as for the suite 1, the Anna Magdalena copy and the Vogler copy are nearly identical.
However there isnt any proof that any of these sources are a direct copy of Bach version, one could very well consider that parts of the suite itself could be spurious. Though it is not the position of experts but with documents so old, a doubt always remains.
The ornament is fairly rare in Bach keyboard works but there are some in his english suites and the partita, for example the sarabande of partita 6. There are present in his autograph so we know he did use it.