In case you don't comprehend how the concept of time works, if I were a subscriber, I would have had the update for ages already. Seeing as I clearly didn't, I'm obviously not a subscriber. How the fuck do you keep going on about sunk cost?
There's no evidence of 0.4.9.5 being ready before April 1st.
All three files on Google Drive were uploaded April 1st late evening.
The commit on Github is dated April 1st as well.
There is no paywalled post on Subscribestar (like there was for 0.4.8.8 and 0.4.8.9, and many other versions).
No one mentioned the new version in Discord public channels before April 1st.
So outside of the very small clique, no one had access to the new version, not even all the thousand subscribers.
As for the version number jump and skipping 0.4.9.1-0.4.9.4, it had happened before: 0.3.4.1 was followed by 0.3.4.5 twelve days later. Probably Inno decided that both of those updates had so little content so adding 0.0.1 was too much, but were not technically just hotfixes so adding 0.0.0.1 was too little, and settled on 0.0.0.5 as a compromise.
In general, Inno published code publicly and the only game-related perk for subscribers is prebuilt binaries for every version (instead of only major versions). This is what is posted under every blogpost announcing a preview build:
I package and release these in-between preview builds for backers over on my SubscribeStar, but anyone can play them at any time by building them directly from the public github (which is always kept up to date with the very latest version)