Unis are just doing what businesses with a lot of exposure to the EU are doing. Opening up the Dublin or Stuttgart office of BigCorp Ltd or BigUni is a hedge against Brexit really meaning hard, irreparable breakdown of UK/EU relations and so is a sensible precaution.
As to why a org might feel the need to take such a step, they are starting to accrue evidence of a cooldown. In universities' cases, funding for research from the UK government was always feeble and rocky, so most advanced programs had to leverage EU funds to get off the ground. Now that is looking shaky, they want to secure their funding. Similarly businesses are being hit with the uncertainty around inward investment. I mean really would you invest in a factory or an office in the UK right now? Whether you were pro or anti-Brexit, you would want for things to settle down first.