Hello!
It does. End-to-end encryption ensures data integrity and confidentiality between you and the recipient. End-to-end encryption must be used, properly and correctly, no matter what (with or without VPN, with or without Tor...).
By adding AirVPN you enhance your privacy as nobody in the middle (including your ISP) comes to know that you and your recipient are communicating with each other (if necessary, you may hide your identity to your recipient too). As the Electronic Frontier Foundation pointed out, knowing who communicates with whom is a sensitive information which can be used against citizens' privacy even when the communication's content is encrypted. In this peculiar sense, privacy enhancement is also a security enhancement.
In this specific case the AirVPN additional protection may or may not be necessary, according to your threat model. Let's imagine an hard case: your threat model includes an adversary which systemically wiretaps your lines. When this happens, hiding to that adversary the location of where you're uploading important amount of data is a layer of protection in itself: it may be a very good thing, and indeed a security feature, to prevent your adversary to know which datacenter you rely to store your data and so on, even when everything is encrypted. This is a real security enhancement (you cancel the knowledge of a crucial access point from the attack surface): even if the adversary can't decrypt your data, it can either destroy them, make the machine where they are stored inaccessible, or further encrypt them to ask for a ransom, if it comes to know their location and cracks the access system.
Avoid it whenenver possible, but there are some cases where it comes in handy. Imagine that you have to cross the borders of a country with questionable practices towards foreign citizens and you want to avoid a compulsory, time-consuming and stressful analysis of your mobile devices or laptop (with the obligation to provide the decryption password, otherwise you will be charged as a criminal). To avoid this hugely stressful and time-consuming action, the usual solution is to upload the complete device image (heavily encrypted of course) to a service that you know you can access from abroad, and download and restore the image well after you have crossed the border. So you can cross the border with a dummy phone/tablet/laptop completely empty of any of your sensitive data, with just a few apps to make the inspection and intrusion quick and painless, or with no device at all, and then buy a new one and restore the image you have stored on some globally accessible server (of course, some passwords must necessarily remain stored in your mind).
Kind regards