Does protecting Kaaba from one attack mean Kaaba protection is guaranteed by Allah?
In addition to the answer provided by @goldPseudo, what happened to Abraha army was in a unique situation, the same year that Prophet Muhammad (PBUH) was born (Year of Elephant - Aam Ul Fil) and in that year some unique events was happened to mention the people around the world that the last prophet has arrived (You may see a list of that events here).
So it does not necessarily mean that if the same attack to Kabba is done at a different time, the same direct protection by Allah will happen again.
Is Kaaba damaged at any time?
Definitely Yes. We already know that during lifetime of Prophet Muhammad Kabba was damaged by flood of water after heavy raining in Mecca (the same event that Prophet Muhammad (PBUH) found a way to install the Black Stone (al Hajar al Aswad) by cooperation of all tribes in Mecca).
After the Prophet, Yazid ibn Muawya army attacked Mecca and fired Kaaba by catapulting fireballs (see references). That time also a similar event did not happen to protect Kaaba by Allah.
If we look the history we may find other times that Kaaba was damaged and rebuilt later.
So who is responsible to protect Kaaba?
We, Muslims, have the mission from Allah to protect Kaaba, exactly in the same manner that before us the small birds (swallows) were given this mission from Allah and protected it from attack of Abraha army.