Technically I think it's more accurate to state:

shrinking a database will very likely fragment the indexes used by the queries run to generate the reports, and that this will impact the performance of the reporting database.

That is, it's not 100% guaranteed to fragment index(es), but it is very likely.

Because of all the factors everyone has stated, shrinking a db to regain a (relatively) small amount of just isn't worth it. Indeed, shrinking the db and then rebuilding the resulting fragmented index(es) often results in a larger db than when you started out!

If you genuinely need to shrink the db, there are some steps you can take to get the more shrinkage with less fragmentation, but it's extra effort.