New temporary sibling dynamics without oldest

Three weeks passed since our oldest child HG went on solo journey to Japan. Here in Georgia home, we've seen some interesting changes with the remaining two, 4-yr old AK and just turned-2 LM, both of whom had never been separated with the oldest brother for this long. Note: Children quickly grow, so we're NOT saying the separation from the oldest son triggered any of  changes.

• No obvious hysteria for their big brother.
• AK became so much chattier. Before, he wasn't a quiet one (at least at home) though, now he's dominant in the volume of the chatters/noise in the household, from 8am in the morning to 7pm in the evening, non stop.
• We aren't sure if LM realized that her oldest brother is not home (Whenever she sees him on the video chat or his pictures, she's delighted).
  
• AK and LM play even more together. Before, they did play together when HG wasn't home, which is great.
• Every weekend, parents are shouting and yelling as much as we've been doing, regardless of the number of the kids we're with. However, the target of "admonition" has shifted from 2 boys fighting to the wrongdoing of either child. Yes both are fairly mischievous, particularly the youngest.
  

Within our kids, the age difference from older and younger siblings is 3. So with AK almost turning 5, we've already experienced once the dynamics of 5-yr old and 2-yr old when HG was 5 and AK was 2. Compared to my memory from that time, this time, with only 3 weeks passed though, we've noticed:

• AK is adjusting to LM's intellectual level. Before, HG never did in my opinion, he was always in his pace, did whatever he was curious about, and AK was trying to catch up with him. Then AK understandably couldn't do most of the times, he wanted to do what HG was doing but AK couldn't execute, resulted in fights, a lot. Now, because there doesn't seem to be many cases where Leila gets frustrated as he can't do what she intends to do, not much fights between them. Yet.
• It's only 3 weeks so we're just monitoring though, I've begun to worry that AK's lack of initiating his own interests. At almost age 5, he deserves having his own interest that keeps him indulged for certain amount of time, doesn't he?
• We've been concerned by AK's aggressiveness since he was 2. Are we still concerned now that HG is gone temporarily? Yes. He often pushes and hits LM. Every time I witness the moment, I ask him what's going on before scolding, then many times his excuse is that he was just playing, and sometimes it did seem they were just playing only in hindsight, but other times don't. That said, he does still attack.

Anyhow, we're doing ok in Georgia, but we miss HG. We chat almost every other day, before him leaving for school is our night time routine. He learnt Google Chat but doesn't message us as much as we wanted. It's ok, he's excited with a new temporary life at grand parents, with new friends, freed from strict parents. Hope he strives to the maximum.
 

LM is never short of ideas for playing by herself, but she chooses to stay with AK a lot.

One new thing we resumed since HG left: run event. As 2 smaller kids can easily be sitting in a double jogger-stroller, combined with covid-19 calmed down we finally participated a run event, for the first time since we moved to Georgia.