No. An expected addition only affects the cost side. The final forecast increases, and the contribution margin goes down correspondingly. Revenue and revised budget do not change.
How to see the effect
Enter an expected addition on a production code.
Look at the key figures Final forecast and Contribution margin (%) at the top of the project.
The final forecast has increased by the amount, and the contribution margin has gone down. On the production code you see the addition under Adjustments in Overview.
Good to know
The original budget is locked, and the revised budget is not affected by expected additions.
If the client is going to pay, register a change order instead. That is what gives revenue.
A negative expected addition lowers the final forecast.