Google has confirmed that the Target ROAS & Target CPA are not going anywhere but are being included within other bid strategies. The Target CPA and Target ROAS will be included in the Maximize Conversions and Maximize Conversion value bid strategies, respectively.
Recommendation:
Google states that the machine learning that powers the Target ROAS and Target CPA bid strategies will not change. There will be no changes, the bid strategies will work in the same way they used to but the way the advertisers can set them up will be slightly different.
How To Set Up Target CPA Bid Strategies
Once the interface update comes out, advertisers setting up Target CPA, advertisers will then need to select Maximize Conversions. After selecting the Maximize Conversions, advertisers then can set a Target CPA. The bidding strategy will work the same as the Target CPA currently does if a target CPA is in place. The Target CPA will be optional and those campaigns that do not use a target CPA will use the same Maximize Conversions bid strategy that advertisers currently have access to.
How To Set Up Target ROAS Bid Strategies
Advertisers that are setting up the Target ROAS bid strategy should choose Maximize Conversion Value. Advertisers will have an optional target ROAS setting. Advertisers that use the target ROAS setting can expect the bidding strategy to be used in the same way that it currently does. Advertisers that give up the target ROAS setting will be utilizing the same Maximize Value bidding strategy that already exists.
Conclusion
The motive of this change by Google is to provide more clarity for the advertisers on which bidding strategy they should use. These updates are expected to be rolled out in the coming weeks and months. Google will give notice in advance to the advertisers before automatically transferring the campaigns to the new strategies.