I asked the same thing on the German MZ forum. The below is the response from Lothar:
as far as I know the used ignition box could produce unwanted sparks as consequence of
glitches or spikes which were produced and propagated by switching load circuits especially the starter relay.
That means it was possible with a small probabilty that any irregular sparks could reverse the
rotation of the crank and could give a killing beat to the starter free-wheel.
To prevent such electrical spikes from the ignition control box input these components were added.
All this shows how chaotic this technical development ran some months after the wall came down and MZ was pressed to defend their position on the market.
I purchased the set because I had an MZ500R in 2002 which hadn´t it. If I remember correctly the set was about 25 EUR.
Analyzing the set I found components of about 1 EUR within...
The photos show the new set and how it was inserted in my MZ500R:
The red components were added in the following part of the electric scheme
I left mine in.