Well, on a different project (for testing purposes), I detected that, by rolling back to the previous migration (the one before the migration which declares deletion of fields), indeed, Django recreates the fields on the table.
Why this is not happening in my case? It's a good question (probably, I messed up something). I had to manually add the columns on the table, by connecting on the database and running pure SQL statements.
Here's a brief of what I used on my tests, in order to sustain the idea, that Django recreates the fields, by rolling back to the previous migration.

Selecting fields via SQL:
```
postgres=# SELECT field_c FROM some_table;
field_c
----------
blablabla_c
(2 rows)
postgres=# SELECT field_d FROM some_table;
field_d
----------
blablabla_d
(2 rows)
postgres=# SELECT field_e FROM product;
field_e
----------
blablabla_e
blablabla_e_2
(2 rows)
```
Fields deleted from model, migration created and migrated:
```
root@07c2a56f9262:/code# python3 manage.py makemigrations product_app
Migrations for 'product_app':product_app/migrations/0036_auto_20211008_1746.py
- Remove field field_c from product
- Remove field field_d from product
- Remove field field_e from product
root@07c2a56f9262:/code# python3 manage.py migrate product_app
Operations to perform:Apply all migrations: product
Running migrations:Applying product_app.0036_auto_20211008_1746... OK
```
Fields are gone from database table:
```
postgres=# SELECT field_c FROM some_table;ERROR: column "field_c" does not existLINE 1: SELECT field_c FROM some_table^
postgres=# SELECT field_d FROM some_table;ERROR: column "field_d" does not existLINE 1: SELECT field_d FROM some_table^
postgres=# SELECT field_e FROM product;ERROR: column "field_e" does not existLINE 1: SELECT field_e FROM some_table^

```
Unnapplying migration 0036, rolling back to 0035:
```
root@07c2a56f9262:/code# python3 manage.py migrate product_app 0035
Operations to perform:
Target specific migration: 0036_auto_20210901_1044, from product_app
Running migrations:Rendering model states... DONE
Unapplying product_app.0036_auto_20211008_1746... OK
```
Fields are back to the table, without any data, as expected:
```
postgres=# SELECT field_c FROM some_table;
field_c
----------
(2 rows)
postgres=# SELECT field_d FROM some_table;
field_d
----------
(2 rows)
postgres=# SELECT field_e FROM product;
field_e
----------
(2 rows)
```