The point being, a nation can go from point a - no diplomatic relations - to point b - having diplomatic relations. Yes or No?
No.
The analogy is made to the experience of the United States from 1776 to 1783. In 1776, several British colonies in North America banded together to declare their joint independence from the Crown. They based their declaration on the right of any people to resist oppression and that the just powers of government are derived from the governed. The declaration was contested by the ruling authority. To enforce the claimed independence, the revolutionaries necessarily resorted to force of arms.
We claim July 4, 1776 as the date of the founding of the Union know as the United States of America because were were able to sustain those claims on the field of battle. The former ruling authority recognized that independence in September 1783. Prior to that time, the United States gained diplomatic acceptance form several other regional and world powers.
First France and the United States entered into a Treaty of Alliance in February 1778. Spain allied with France against Britain in 1779, but did not officially recognize the United States. That came in February of 1783. Soon thereafter diplomatic recognition came from Sweden, Russia, and Denmark.
Prior to September 1783, the United States could only claim to be an independent nation state. After recognition by the former ruling authority, and by other world powers, that nationality became an uncontested and accepted fact.
By analogy with the so-called Confederate States of America, their existence was contested by the ruling authority. They were never recognized as a legitimate nation-state by any regional or world powers. They never entered into treaties with those powers. They never exchanged ambassadors with those world powers. They were never able to enforce their declarations of secession. They only existed as an illegitimate insurrectionist government.