If you add new places/numbers behind the point (right side), its deflation.
If you add new places/numbers before the point (left side), its inflation.
Discussion
No zaps set up?
The interesting part is that you're wrong and right at the same time!
Adding decimals increases the value of the network as more humans can access it as a unit of account & medium of exchange - meanwhile increasing the accuracy of payments for everyone.
New Bitcoins will be distributed to miners that were never in existence though.
So the net effect will be deflationary - as we can't exceed the ~21M barrier by adding decimals & surely we'd be doing this for people clamoring for it as Satoshis become more valued for goods and services.