気になったので検証してみました。
同じ結果になりました！
「3.3.3.3」宛のルート情報がルーティングテーブルに載っていないですね。

RA#show ip route eigrp
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      2.0.0.0/32 is subnetted, 1 subnets
D        2.2.2.2 [90/130816] via 192.168.1.2, 00:07:58, GigabitEthernet0/0
D     192.168.2.0/24 [90/3072] via 192.168.1.2, 00:07:58, GigabitEthernet0/0

RAのEIGRP（IPv4）の設定

!
router eigrp 1
 network 1.1.1.1 0.0.0.0
 network 192.168.1.0
!

RBのEIGRP（IPv4）の設定

!
router eigrp 1
 network 2.2.2.2 0.0.0.0
 network 192.168.1.0
 network 192.168.2.0
 eigrp stub connected
!

RCのEIGRP（IPv4）の設定

!
router eigrp 1
 network 3.3.3.3 0.0.0.0
 network 192.168.2.0
!