Freezing and defrosting Cantaloupe is still good in the fridge?

It should be healthy for now (assuming it was still relatively fresh when you put it into the freezer) but will actually break down faster now that you have frozen and thawed it. It will also have a much softer and significantly less pleasant texture than it did before, although that won't have much effect on blending.

When you freeze foods, the water in the food forms ice crystals, which are very sharp and which puncture the cell walls of the frozen food. These punctures cause the cells to lose a lot of water when the food is thawed and their water becomes liquid again. You will probably notice that your cantaloupe will look somewhat translucent and will have a lot of juice in the bottom of its container. This is due to cell damage and water loss post-freezing.

In fruits and vegetables, cell walls provide the structure that forms the fruit's texture, and damaging these walls will significantly weaken that structure. So the cantaloupe will be less firm and a lot less pleasant to eat on its own. It's probably still safe for now, but puncturing the cell walls will also make it easier for stray bacteria to get to the food's sugars and start multiplying, resulting in faster spoilage.

I would recommend using this immediately; failing that, 3 days maximum in the fridge would be as far as I'd go. If you want to do this in future, just leave the cantaloupe in the freezer until you're ready to use. Assuming it's tightly sealed to avoid freezer burn, it will keep for up to 6 months there.