Couple of milestones before that:

- flying reused booster + Starship

- longer in orbit missions for Starship of weeks or months. There are some non trivial issues with that probably; and you'd need that to not make refueling pointless.

- having two active launch sites. Nor strictly required but probably handy if you are going to have two Starships in orbit at the same time.

They might not get to all that in that order. But the important step today is that they get to inspect a "flight proven" Starship without water damage. I bet they are going to learn a lot of details of where exactly they need to iterate and improve. This took them some time with Falcon 9 as well. We've gotten used to this thing basically launching and landing without many issues. But that wasn't always the case. 2027 is probably going to see an increase launch rate.

Moon landings are going to be an interesting one because it depends on NASA as well and the decision making around that is very political. On the other hand, there's going to be increasing peer pressure from the Chinese. They have their own plans and it doesn't involve waiting for NASA to get there first. They are targeting 2030 for a manned mission. I expect the politics might get a bit more opinionated on that topic as that gets closer. The long term game here is not just landing and planting another flag but actually establishing a permanent presence on the moon. That involves flying useful payloads back and forth. Starship seems designed for that.

What happens after that is going to be an interesting one. IMHO, Starship is optimal for earth landings but not necessarily for the moon and Mars. What's currently flying is probably over engineered for a place with no atmosphere and one 6th of the gravity (the moon) or a very thin atmosphere and one third of the gravity (Mars). Would those flaps even work in the Mars atmosphere? However, it's a great launch vehicle to get components in space to build something more optimal. Also the booster might be used to launch other things than Starship. Like something that will never come down and can instead be fueled for deep space missions and Mars/Moon landings.

They did refly one of the boosters already.