Not directly. If you are after a measure of anisotropy and you don’t need FA, you can use the command sh2power -spectrum to calculate the power spectrum of the template FOD. The l=2 term (2nd volume) is conceptually comparable to FA.
If you need FA and if you saved the warps (-warp_dir) you can apply these to FA images generated from the dMRI data (dwi2tensor, tensor2metric) that were used to generate the FODs via mrtransform -warp_full and average the transformed images using mrmath (if not all images cover the full area of interest, after transformation you’d need to nan-mask areas outside the transformed masks using mrcalc.
If you don’t have warps, you can re-register the subjects’ FODs to the template (as in the FBA pipeline) and use these warps to transform the subjects’ FA images to template space but the two templates wouldn’t be 100% comparable as registration procedures inside population_template differ from directly registering a subject’s FOD to the final template.
Another option is to recreate the template using FOD and FA contrasts which would generate the template for you. You could set the multi-contrast weights for FA (-mc_weight) to zero if you do not want FA to contribute to the registration.