We will have a quantum resistant Bitcoin network, there is no doubt. But we will have two main Bitcoin forks post quantum.
The question is which of the two main Bitcoin forks will be supported.
1. A Bitcoin blockchain with all existing coins (also Satoshi's early mined coins and other early mined coins with no owner). Here the QC owners will remove those coins and will be the new owners and the community 1 of this fork will accept it as a reward to QC owners. If there were owners of early mined and not moved coins, they could have moved these coins. As they didn't, the community 1 will handle them as "lost" coins.
..once Quantum Technology becomes a realistic threat will be those coins that are effectively "lost". The QC owners will become the new owners of those coins, and Bitcoin will carry on as it always has.
2. A Bitcoin blockchain without the early mined coins. Community 2 will not accept it that someone (QC owners) gets the early mined coins and will burn them.
Should coins that were mined early and are deemed inaccessible were retrieved by QC owners and the community knew about it, perhaps a fork would be proposed and we'd take it from there and accept the fact that these coins are permanently lost in the void without any chance of retrieval.