I think this is salesman nonsense trying to minimise anxiety . My local dealership has a back log of updates and cant do mine until at least November. (I'm surprised they have sold so many Jazz
)
I've driven my (RHD -UK) Jazz in Eastern Europe (Bulgaria ,Romania, Hungary , plus Greece and various other EU countries.) And I have driven other cars in many other non eu countries such as Serbia,Northern Macedonia ,Bosnia-Herz, Montenegro. For the most part the signs are frequently displayed and exactly the same design as the rest of Europe and my car had no problem reading them. If they are there.
Many countries use alternative methods of denoting where the urban speed limit applies such as a town sign and may not display speed limit roundels.Making the system somewhat redundant. .
(Jazzik has shown the signs used in Poland on a recent post)
No update is going to allow the system to read signs that are not there.
I suppose there might be a few signs where it struggles Occasionally ,although of the same basic design a no overtaking sign might show car outlines that look like they date from the 1930's. .
There is a bridge near me in England that still displays a sign "No charabancs". I dont suppose it will read that either - fortunately the Jazz is not a Charabanc.
Whats the betting Jacob Reese -Mogg will want to replace the international Bus symbol and revert to these signs from the 1920's.
That said ,my car has displayed conditional speed limits (if its snowing) where there was no actual sign displayed .I assume a few are programmed in as gps coordinates. Its just possible they are updating these. But I dont think thats what the recall is all about. I think you are being fed bovine droppings.