Austrian "excommunication" reports are a-muddle
First, the canon under which Bp. Laun is said to have acted is 1983 CIC 1041, n. 1. Although related to abortion and homicide, this is not an excommunciation canon, but rather, an "irregularity for ordination" provision. Somebody (the bishop or the press) is way, way off in citing it. Second, auxiliary bishops are not usually the lead players in major sanctions cases, and there is some ambiguity as to whether an auxiliary bishop can even take this kind of step under 1983 CIC 1341; presumably, diocesan bishops are the decision-makers here.
Finally, as I've said many times, canon law imposes excommunication only for a very narrow range of actions; renting space to an abortion clinic isn't among them. Maybe it ought to be, and maybe there's some other way to visit penal consequences on what is obviously an objectively gravely immoral action; but as of now, even if the right diocesan officers were citing the most relevant canons, there is no excommunication in canon law for the act described.