So we have 2 items to discuss, the authorization issue and the envoy long term data.
Next became a long story. Shortly, firmware d7.0.88 is known to fail with current HA and rename entity_ids of entity’s (not entity name or envoy name), remove old and add new envoy.
Authentication issue
As for the authorization issue, nothing wrong with your Enphase account or the token. In the log it can be seen that the token is retrieved and still valid.
When it tries to read data from the Envoy it receives the not-authorized status. This problem is typical for the D7.0.88 firmware. (See Github issue 148028). Which brings the question which firmware your old envoy was running?
The debug log shows you have no current transformers (CT) installed, Is your a Envoy-S non-metered EU one? I have such a one for 3 years now and it is on D8.3.5167 as of last summer.
Entity long term history
As for the names topic. The integration uses the serial number read from the Envoy to create all the names. Renaming the gateway itself will not help.
A starting Envoy integration uses the unique_id of entities to find these in the configuration data. The unique_id contains the envoy serial number. In the configuration data the entity_id stored. It uses the entity_id to find the history/statistics data. And the entity_id also contains the Envoy serial number.
If it can not find its entities through the use of the unique_id, like in the case of a different envoy serial number, it will create new entities with new unique_id and new entity_id, both with the new envoy serial number in it. It then checks if the entity_id exist in the history/statistics tables, and if not, create new empty entries and start using these. When adding a new Envoy with a different serial number, all entities get created with the new serial in the unique_id and the entity_id and all history starts fresh.
In current versions of HA, one can change the entity_id of an entity. When that is done, the entity_id in the configuration is changed as well as in the history/statistics tables. All still connected as before. Upon deleting the envoy, the history/statistical data is kept, only configuration data is marked as deleted.
By renaming the entity_ids of the old envoy to contain the new Envoy serial number, the new serial will be in the statistics/history entries. When then deleting the old envoy that data is kept. And when then adding the new envoy it will create new entities and connect these to the renamed entities in the statistics/history data.
So you will have to go into the entity list, find all old envoy entities and rename the entity_id (not the name, but the entity_id field). Then delete the old envoy and add the new one. (But that will fail because of above described issue)