If it were a refrigerator I might say yes, but it is marginal that a water heater might have damaged the flooring unless it was full. Is there anyone else in the home who can test the area and help double-determine if there is indeed a change? It might have been best to lay down some 4x4 plywood sheets to help distribute the load along the pathway. I doubt the plumbing people would agree to replace your entire flooring for this.

They did empty the old WH but it was still pretty heavy. I'm not planning to ask the plumber to do anything with the floors.

My floors have been discontinued so I was more asking to see if I need to try to locate and buy extra flooring. So I have it when ________(whatever the smart people on the forum say may happen in the future) happens. The area is the main walkway in my house. It's open concept so I wouldn't be able to replace it with a different floor at some point. I'd have to replace all of the flooring if I don't have the matching pieces. I'm in a small place so I don't I really have extra storage space especially since the boxes would need to layout vs leaning against a closet wall. But I guess I could store them under my bed.

I live alone so noone else would really notice a change like I would.

Having extra flooring is always nice, but if you don't have room to store it, I would say no on that one, just my personal opinion. Laminate flooring does have a shorter lifespan than some other types of flooring, so you may find in time that you'd want to replace everything anyway. Having a smaller home is on your side in that respect as newer flooring wouldn't be overall as expensive as in a larger square footage space. Some types of flooring like cork or Marmoleum can be placed on top of linoleum saving removal costs. Cork and Marmoleum also have limited lifespans compared to more durable surfaces like hardwood or tile. If the water heater was emptied, I think the chances of your subfloor having been damaged without seeing any topical damage to the linoleum is slim. You may just be noticing the area more out of concern for the intrusion?

How old is the laminate floor? Was there an underpad laid underneath before the laminate was installed? Are you on concrete slab or over wooden floor joists?

You say the floor is continuous...do you have t-moldings in the doorways?

It is possible (the laws of physics being what they are) the dolly they used to wheel the old tank out caused some compression to the UNDERPAD of the laminate. The 'crush weight' of the underpad is what you would be looking at (no one publishes this sort of thing...it simply isn't available to view).

I doubt the laminate has been disturbed. I would give it a few weeks to sort itself out. Somethings take time to 'decompress'. We are also in a transitional season (spring and fall are the two seasons where we transition from expansion/contraction settings).

The winter months see the floors contract (dry winter air causes things to dry out = contract). Spring is the season where the indoor situation changes to the summer 'expansion' time. The cracking/creaking you hear could also be part of that transition. When you add the 'crush weight' to the time of year, you might find yourself in a situation such as having a floor that feels bouncier + some noise creation.

Do you hear the creaking more so in the mornings?