These particular sand-coloured FGSOs really were intended by the city as bike "infrastructure", specifically where they couldn't fit real bike lanes because the street was too narrow and it was a bus route so they couldn't make it one-way. See e.g. the article here: https://www.provelozuerich.ch/wp-content/uploads/2016/02/vj_regio_16_5_ZH.pdf (page 3).

That said, I see the point that this intent isn't very verifiable as FGSOs are used so randomly by communes.