How scripting will be impacted if application starts opening in tabs instead of windows.

I work in Siebel application. I have recorded and replayed flows in which;

1) Whenever I click on Siebel button from a portal, then Siebel opens in the same window.

2) Whenever I search address, name from the portal, then Siebel opens in a new window.

Hence, in any case Siebel will always open in a window.

Also, if user wants to close Siebel session, then it just needs to click on close(X) of the window and that is the only way.

But, now, in both of the above cases (1 & 2), Siebel will open in a new tab. There will be no window thing.

Question: What would be the impact on existing script due to this change? Will Siebel tab be used automatically by script?

Kindly reply.