No, I think there are not. At least not at the scale of the proposed projects. I say this just because CO$_2$ makes up only a 0.04% of the atmosphere, so even if you burn fossil fuels until you double the pre-industrial amount of CO$_2$ and then capture and bury it back (both the Carbon and Oxygen). You would only drop Oxygen levels from its current 20.95% to 20.91% or something like that, which is not very significant. In a closed space like your bedroom for instance, you would probably make a bigger change in the Oxygen level by just breathing inside for a few minutes.

Also, many chemical reactions that sequester Oxygen and are sensitive to its concentration (oxidation and combustion for example) would work towards keeping equilibrium: they will slow down if there is less Oxygen allowing the concentration to bounce back. Or they will accelerate if there is too much Oxygen, dropping the level back down.

No, I think there are not. At least not at the scale of the proposed projects. I say this just because $\text{CO}_2$ makes up only a 0.04% of the atmosphere, so even if you burn fossil fuels until you double the pre-industrial amount of CO$_2$ and then capture and bury it back (both the Carbon and Oxygen). You would only drop Oxygen levels from its current 20.95% to 20.91% or something like that, which is not very significant. In a closed space like your bedroom for instance, you would probably make a bigger change in the Oxygen level by just breathing inside for a few minutes.

Also, many chemical reactions that sequester Oxygen and are sensitive to its concentration (oxidation and combustion for example) would work towards keeping equilibrium: they will slow down if there is less Oxygen allowing the concentration to bounce back. Or they will accelerate if there is too much Oxygen, dropping the level back down.