Considering that the number of patches submitted was quite limited I don't think the original research paper would qualify as a DoS attack. The workload imposed by the original research appears to have been negligible compared to the kernel effort as a whole, no more than any drive by patch submission might result in. So no, I wouldn't personally view that as harmful.
As to the backdated review now being undertaken, as far as I'm concerned that decision is squarely on the maintainers. (Honestly it comes across as an emotional outburst to me.)
Wasting time is nor considered stealing. If it were, there is a long queue to collect money from: all the add agencies, telephone menues where you have to go 10 level deep before you speak to a person, anyone who is bothering people on the street with questions, anyone making your possessions dirty would be a criminal. Anyone going on a date that doesnt work out would be a criminal.
Sure, but I'm still going to be pretty annoyed with you. And if you've wasted my time by messing with a system or process under my control then I'm probably going to block you from that system or process.
As a really prosaic example, I've blocked dozens - if not hundreds - of recruiter email addresses on my work email account.
As to the backdated review now being undertaken, as far as I'm concerned that decision is squarely on the maintainers. (Honestly it comes across as an emotional outburst to me.)