Can I receive paper invoices at no extra cost?

Yes, that is correct and still holds. Members of the public have the right to receive paper invoices. 

The Code général des impôts (article 289 5:VI) says electronic invoices may only be used if the buyer agrees beforehand.

The official information site service-public.fr states (www.service-public.fr/professionnels-entreprises/vosdroits/F23208) that acceptance must be formalised and a firm cannot simply start producing electronic bills and inform you of the change.

There is also a specific decree relating to factures from telecom and internet companies that says customers should be informed of the kind of bill they will receive on taking out the contract.

If they later want to change to paper from electronic, the customer must be able to do so free of charge by simply informing the company.
When it comes to bills between firms, or firms and state bodies, it is different and new laws are in place.

Businesses are obliged to accept electronic bills, a rule that has come in progressively and applies also to micro-entreprise independent
workers as of this year.

In some cases, use of electronic factures is now obligatory. When a company bills a state sector body, notably, it must now do it with an electronic invoice via a special web portal called chorus-pro.

This has also been brought in progressively, starting with the largest firms and including even the smallest ones as of this year.

Later, the government intends to impose use of electronic bills between any two firms subject to VAT, between 2023 and 2025, depending on the sector and size of firm.