I heard / was told that since then the 'old addresses' are not good anymore and I need to do something like get a new address and transfer the coins from the old address to the new address?
You must have heard about "
Quantum Supremacy" which will make old unspent P2PK outputs vulnerable.
That includes both old and new reused addresses which have their public key exposed.
But the rumor is more of an FUD since it still decades before Quantum computers can become a threat, don't sweat it.