No, it's just not functional and Bandai just forgot it existed, we all lost our digis if not downloaded, noone can use online features, and no longer checks for cracked or custom dims/bems
as i said, this is not how these things work. this is directly from the bandai website.
https://toy.bandai.co.jp/special/vb/digitalmonster/
Currently, we have found some websites and SNS contents that illegally duplicate and upload the character images and programming from the Digimon Vital Bracelet Series.
Bandai and Toei Animation have never given any license or permission to duplicate, upload and sell the images and programming.
There are several intellectual property rights such as copyrights and trademarks regarding characters, programming, character names of the Digimon Vital Bracelet Series, Dim Cards and any other Digimon series.
Intellectual property law in Japan, the European Union, the United States, China, and other countries protects these rights.
if you can legally do your own app using the device, you can do so regardless of abandonment of the original app. if you cannot do so, abandonment of the manufactorerers app has no impact on this. just make sure they cannot not sue you. because on their website they talk about taking down third party things.
lol. i did not help you. i just wanted to point out that a company abandoning a thing does not protect against getting sued.
the warning on their website seemed rather specific, so it might just be allowed if you do not do those things in your app.
i mean, a lot of the old game consoles also have new things being made for them, and you can find those on itch. you can download new roms for gameboy and others.