I think that change was to prevent a different fraud: using the return portion of an Origin - Destination Plusbus period return ticket on buses in the destination town on more than one day within the validity of the railway ticket.
In Germany, they get around this by taking advantage of the fact that nearly all tickets are booked by looking up a connection and then booking a ticket that is valid for that connection, rather than simply issuing a ticket "from STP to LEI via Any Permitted" or whatever, even though such a ticket will be valid on other services and possibly other (permitted) routes as well. (For print-at-home, this suggested connection will be printed on the ticket as well; at the ticket office or a TVM you'll get a separate slip with the suggested itinerary.)
If you buy such tickets with the +City option (roughly equivalent to PlusBus but including local rail, tram etc. travel within the appropriate PTE boundaries), they will say that that the +City option is valid only on dates X and Y (being the dates of the Out and Return portion of the connection), even though the tickets themselves (if Anytime rather than Advance tickets) are usually valid for two days in the Out direction and thirty in the Return direction.
This does mean that if you return earlier or later than you had originally planned, you can't take advantage of the +City option for local travel to the station. On the other hand, you don't pay extra for +City; it's automatic if you book with a Railcard discount and the originn and/or destination is inside an area that has +City. (Used to be just the destination, but now you can have +City at both ends!)
If you don't have a Railcard, then you can get "City Mobil", which also lets you travel on local transport at one or both ends, but you have to pay extra for that and what you get is essentially a PTE day ticket which you pay the appropriate price for. So the only advantage is that you don't have to have the exact fare and don't have to navigate unfamiliar PTE TVMs at the destination; you don't save any money. This is more like PlusBus, I suppose, except that it takes advantage of the wide availability of PTEs in Germany, rather than creating a "surrogate PTE" in the form of PlusBus in order to be valid on busses of multiple operators.
