I think bollards should normally be fine for cycle routing, but it's possible. Some routes do go through there, so it doesn't seem to be a complete blocker.

Some examples of routes that seem to needlessly avoid it:

https://www.openstreetmap.org/directions?engine=fossgis_valhalla_bicycle&route=51.52724%2C0.00435%3B51.53237%2C-0.00867#map=16/51.5304/-0.0015

https://www.openstreetmap.org/directions?engine=graphhopper_bicycle&route=51.5272%2C0.0043%3B51.5347%2C-0.0068#map=16/51.5310/-0.0004

https://www.openstreetmap.org/directions?engine=graphhopper_bicycle&route=51.5293%2C0.0048%3B51.5342%2C-0.0067