No worries. Storage can be divided into 2 (generally) primary and secondary (or tertiary). Primary is likely to be accessed a lot, secondary not so much. Tapes are used for tertiary storage mostly. So stuff like 7 years records and such like, where you run a report and the tapes can kick in (perhaps even be put in by a human).
For us that would be like archive nodes 
If I understand the IBM info right it seems like the new tape storage solutions could be used by companies like Netflix or similar, with speeds above 350MB/s, closing in on last gen SSD’s.
But as you said it is probably for data which is stored long-term and not erased or re-written.
Given multiple people could be watching a video at any time, I doubt tapes would be a good idea. They are terrible at random access, which would be needed for streaming two different parts of the same video.
Tapes are a backup medium and as you say not good for random access. Even the old 8/9 track tapes used in mainframes of old were mainly for sequential reading/writing. And back then disk drives were not so fast and thus they had their place in bulk online storage. But with todays disk/ssd technology the tape drive is not useful as random access as days of old.
And of course once we talk of retrieving a chunk and being quick enough to be rewarded, well the tape drive would only be starting its seek and the chunk will be at the requesters machine already.
The speed quoted by IBM is sequential speeds and only useful to netflix when they use a hybrid system where a movie requested is read off tape and stored on disk. Then on a cache algorithm it would be removed from disk when space is needed for a new movie. This would save on expensive SSDs/drives because they do not need to store rarely viewed movies on them. It could see them requiring 1/2 the number of fast disks.
But for Safe nope. Safe is demanding 1MB random access with sub 100 millisecond response. Netflix does not require anywhere near that response time. You select the movie and by the time play is hit, it could be 10 or 20 seconds up to minutes since the viewer reads the description sometimes. In this time the tape drive is seeking the movie and starting the transfer to disk.
