My understanding is that this is a 3rd party that may even be breaking Amazon's own rules so this may not come to fruition. Also it would be tied into a Skill so you can just stop using annoying Skills.

Alexa is already too "wordy" though. Many error messages and other responses need to just shut up and use fewer words or be changed to a sound effect. If an ad or any other piece of voice lasts 15 seconds, that sucks on this platform and even advertisers should understand this.

I am reminded of old Star Trek series and I am always laughing at voice interfaces. The ship is accelerating out of control and is about to explode, the crew is asking the computer for VITAL information that should be provided as soon as possible, and yet the voice babbles something like: "Warning, at risk of structural failure, at current acceleration, the ship will explode in 15 seconds" (most important detail last, and the computer used up 10 of your final seconds just speaking it to you).

Was concerned that this was Amazon injecting ads into every skill or interaction.

This is actually just a new ad sdk for skill developers.

So this is only for third party skill devs who want to monetize their own skills.