Figured i'd update you guys on this post with more detailed info
So after seeing mixed suggestions I went on and tested out all 3 options at once by myself. Here are some results
Channel 1 - fresh new, new phone, new gmail and basically just a new account received 0 boost from Youtube. All the views it has generated so far in 10+ days comes from Search and some from Shorts section. I'm talking about 10-20 views at best on the channel for 33 shorts + some other long format videos.
Channel 2 - Old aged with 4k+ subs and millions of views in the past, uploaded 4 shorts, pretty much the same result couple of views from notifications/browse but none from the Shorts section, leading me to believe that deleted videos do affect the channel negatively (no surprise here, since metadata stored from videos basically goes away and channel loses the reputation it has built in the algorithm with those videos)
Channel 3 - Now this one is doing better, the channel was in a very different niche than my Shorts content so I chose to somehow pivot my viewers by connecting current channel niche to my desired niche. The channel itself was created 10 months ago and has generated 5k subs and couple of million views. It was an active channel with only long-format videos. Users engaded in videos,community,etc. I posted 6 new shorts in a span of 5 days and most of them reached 10k view mark within a day and then started passively generating some views.
Conclusion: Channel 3 performed best the quickest amongst the other 3. Obviously Channel 1 will perform better in the long run once it has established itself in the niche and YT starts promoting it on its own.