If someone is remortgaging does that indicate something good or bad

Remortgaging (known as refinancing in the USA) is the process of paying off one mortgage with a loan acquired from another lender. People do it for a variety of reasons. They might find a lender who offers lower monthly payments, or the new loan may have a fixed interest rate while the previous one didn't (allowing them to be more certain of their future finances). So it could be that the "someone" in your OP took this decision for sound financial reasons.

However, people also remortgage when they want or need a lump sum. If they can find a new lender who is willing to loan them more than the amount they'll have to pay off, they can use the difference as they wish.

Obviously, the loan is secured against the property, so they could end up in serious trouble if they can't keep up the new repayments. And they obviously also end up owing more than they did before, so their equity in the property decreases. But many people are willing to do this if they're convinced that the value of their property will constantly increase in the future. They believe that when the time comes for them to sell, what they'll get will inevitably be at least as much as what they need to pay off the total debt.

If, as has been the case in the UK for the last few years, house prices continue to increase at an annual rate of around 10%, that will probably work out. However, if - as has happened in the past - house prices fall, then people can find that what they receive from the sale of their house is less than the value of their mortgage debt. That means they're really in the financial shit.

Usually not the best sign.

I'm looking at remorgating to get money for some home repairs, and when I'm all done I should end up with lower monthly payments.

Yes, I will own longer on the house. But, I have flat roof section on my house that's about 67 years old that needs to be replaced, the garage roof needs replacing, and there are other exterior repairs that need doing.