Warning!
Beware, YouTube and Google Ad Manager (if you choose it as yours ad provider, formerly also known as DoubleClick for Publishers) are both properties of Google. adwire uses Google IMA SDK to handle ads, which is also property of Google. Due to these dependencies on Google, you might be risking your Google account to get suspended or even banned in case of any violation. Check your contracts with Google for more information.
Technically speaking, adwire temporarily removes YouTube iframe embed and replaces it with linear video advertisement according supplied AdTag. When linear video advertisement is finished, YouTube iframe embed is restored and automatically played for seamless user experience. Therefore there is no advertisement and YouTube embed on screen at same time.
By using adwire (and setting terms option to true), you take full responsibility for risks mentioned above.