But, if the transactions are legitimate, the previous nodes do not know the place these cash obtained spent. Are they seen as misplaced cash?

Previous nodes do know the place the cash are going, because the transaction format did not change. It has inputs and outputs. Taproot inputs are seen as legitimate by pre-taproot nodes (together with taproot-invalid taproot inputs, in fact, as they cannot confirm the foundations). However nothing modified about the remainder; pre-taproot nodes nonetheless:

• Require that UTXOs referenced as inputs exist, and mark them spent
• Create new UTXOs for all outputs within the transaction
• Implement the sum of the enter quantities is no less than equal to the output quantities
• …

What occurs when a Taproot transaction is adopted by a previous model transaction such that UTXOs are again to being accessible for spending as an old-style transactions?

There is no such thing as a such factor as a taproot transaction. Taproot validation guidelines are a per-input idea, native to its script validation. The whole lot else a few transaction with a taproot enter is unchanged.

The successor transaction is simply validated usually.