Do Githzerai hatch from eggs?

Question

We know that Githyanki hatch from eggs from this question.

Is there a specific source that says the Githzerai hatch from/lay eggs?

Answer 1

The Githyanki and Githzerai are both Gith

Mordenkainen's Tome of Foes details that the Githyanki and Githzerai are simply two factions of being a Gith:

But after they won their freedom, two factions among the gith disagreed on what kind of civilization they would forge.

The factions are mechanically described as sub-races of Gith, not as separate races. The descriptions begin with the standard Gith, and then provide the specifics for the Githyanki and Githzerai. This similar to the primary heading of Dwarf and then choosing Mountain Dwarf or Hill Dwarf. Many races have subraces (halflings, elves, etc.).

With this in mind, the linked question you begin with on whether Githzerai lay eggs remains the answer to this one: They do (MM, 87).

Githyanki hatch from eggs.

Answer 2

The Githyanki and Githzerai are warring factions of the same species, Gith.

From MToF:

But after they won their freedom, two factions among the gith disagreed on what kind of civilization they would forge.

These factions are later described as the Githyanki and the Githzerai.

Further, MToF lists the two as subraces of Gith. No matter which you choose to play, the race details state, "Your character shares the following traits with other gith", then goes on to detail the specifics of each subrace.

The confusion is understandable, twice in MToF the two are referred to as "two races", but I do not see any reason to believe that the Githyanki and Githzerai are different races in such a way that their biology would be so fundamentally different that one would lay eggs and one would not.