Spine disallows moving attachments and meshes at the same time by design, so what you experienced is expected.
As previously mentioned, the steps you described would still cause you to repeat the translation process for each image in a slot, and also for each skin, so a more effective way is the one I described above.
Thank you for taking the time to let us know of something you suspected to be a bug! 😃 sometimes they are not, sometimes they help us improve Spine!