These answers are taken directly from the Ethereum Foundation development team. These aren’t coming from me rather the individuals who are currently working on the merge, /u/vbuterin included.

Triple Halvening? explained:

There is little to "believe" in: it is just a matter at looking at PoW versus PoS issuance. Right now PoW issuance is roughly 13,500 ETH/day. In comparison PoS issuance with 14M ETH staking is roughly 1,700 ETH/day ETH per day. So even with 14M ETH staking (for context we currently have 5.7M ETH staking) 1,700 ETH/day is roughly 8x less than 13,500 ETH/day and an 8x issuance reduction is the equivalent of three halvings in Bitcoin land.

Ultrasound Money?

Likely soon™. A criterion for qualifying as ultra sound money is decreasing supply which could be achieved post-merge if fee burn from EIP-1559 is greater than PoS issuance. I have high confidence (95% ) that the supply will start decreasing post-merge and that the supply at merge (projected to be around 120M ETH) will be a de facto supply peak for the lifetime of Ethereum. Note that monetary deflation implies "No Supply Floor™", as David Hoffman would say :)

I’ll be editing this adding a few links to learn more about ultrasound money later on.

TL;DR: The triple Halvening will happen. There will be a limited supply of ETH after the merge, and the projected coin limit is 120 Million. Lastly, ETH 2.0 will be defined as ultrasound money.