A university does not allow its employees to use its affiliation on papers done in spare time; how normal is that?
Generally the opposite is true in the United States -- the university wishes to have jurisdiction over all work done using university resources -- which includes the laptops and computers we use. Since faculty are exempt employees presumably we have no "free time," but instead work 24x7 for the university (except for the summer months for 9-month employees). So basically any idea that I come up with from August to May of the calendar year and that I use my school resources to work on, is the property of the university unless specifically disclaimed.
Just ask your patents and licensing office to sign a document saying that your university hereby releases you of all possible intellectual property and inventions that may come out of your paper (even if it's in History!) and see if they change their tune.
Note also that many American universities require their faculty to fill out a "Faculty Activity Report" every year that details all of their publications (as well as service/teaching work). The university uses it internally to determine promotions and retention; but it also forwards this data to organizations such as the National Research Council -- that determine university and department ranking using criteria such as number of publications.
Thus it is in the university's best interests (both for IP and for ranking purposes) to capture every single faculty publication that it can. So I would think your scenario would be implausible for most R1 universities in the USA, at least.
Let's call a spade a spade here:
This policy is not common. I have never heard of a faculty member in a developed country being dictated to in which area to publish or being limited in using their university affiliation only when publishing in certain areas and not in others.
This policy is not logical. Let's see, who is more competent to judge if a faculty member is qualified to produce high quality research on a subject? (a) The faculty member and the editor and referees of the journal they submitted their paper to; or (b) some clueless university administrator?
Simply put, this policy ignores centuries of history that have developed academia into the bastion of creativity and free thought that it is, and proved that the academic model is one of the best models humanity has discovered for creating new knowledge. (Yeah, yeah, to the cynics among you, go ahead and feel free to kill me for this comment, and bring up everything that's wrong with academia nowadays...).
This policy is not surprising. This story establishes that there is at least one university somewhere in Western Europe that has at least one policy-maker who is, let's say, not the sharpest tool in the shed. I am shocked, I tell you. Shocked.
tl;dr: Endorsing such paper bears high risk and promises a low reward.
Long answer:
Not many academics these days write outside of their narrow scope of expertise. Clearly, there is no general policy or practice of how institutions deal with such rare situations as they occur; every administrator probably comes out with an ad hoc solution based on their personal understanding of what's appropriate.
I can think of several reasons why a University may want to disassociate from a Paper written by a Professor in a new Field.
- The Professor may think they have made a breakthrough in the Field, whereas in fact (s)he only scratched a surface of a subject, or understand it completely wrong. One example is Fomenko's New Chronology but I'm sure there are more.
- The Field may be highly controversial by its nature (e.g. politics, social science, religion) and Professor may lack understanding how to present the argument in a way which avoids potential conflicts and accusations. The University does not want to be involved in potential scandal, and avoids it.
The higher risks of endorsing the Paper come together with a reasonable low reward. It is less likely that someone completely new to the Field come out with a suggestion which will have a transformative effect. Unless the Professor articulates that they firmly decide to move to this Area (change Departments, attract new research grants, develop new programs, supervise new PhD students), the University does not really benefit much from the Paper.