Tightly packed struct fields and post-upgrade storage slot conflicts

Smart Contracts
1

According to the storage layout in Solidity, a and b are tightly packed together in one storage slot. This will also be the case in the v2 version of the contract where a, b, and c will be packed together in one storage slot. Is this a problem in terms of upgradeability and maintaining the original values of a and b from the v1 contract version?

In ContractV1:

struct MyStruct {
  uint8 a;
  uint8 b;
}

mapping(address => MyStruct) myStructs;

In ContractV2:

struct MyStruct {
  uint8 a; 
  uint8 b;
  uint128 c;
}

mapping(address => MyStruct) myStructs;